According to Merriam-Webster's online dictionary: "Main Entry: 1time Pronunciation: 'tIm Function: noun Etymology: Middle English, from Old English tIma; akin to Old Norse tImi time, Old English tId -- more at TIDE 1 a : the measured or measurable period during which an action, process, or condition exists or continues : DURATION b : a nonspatial continuum that is measured in terms of events which succeed one another from past through present to future c : LEISURE <time for reading> 2 : the point or period when something occurs : OCCASION 3 a : an appointed, fixed, or customary moment or hour for something to happen, begin, or end <arrived ahead of time> b : an opportune or suitable moment <decided it was time to retire> -- often used in the phrase about time <about time for a change> 4 a : an historical period : AGE b : a division of geologic chronology c : conditions at present or at some specified period -- usually used in plural <times are hard> <move with the times> d : the present time <issues of the time> 5 a : LIFETIME b : a period of apprenticeship c : a term of military service d : a prison sentence 6 : SEASON <very hot for this time of year> 7 a : rate of speed : TEMPO b : the grouping of the beats of music : RHYTHM 8 a : a moment, hour, day, or year as indicated by a clock or calendar <what time is it> b : any of various systems (as sidereal or solar) of reckoning time 9 a : one of a series of recurring instances or repeated actions <you've been told many times> b plural (1) : added or accumulated quantities or instances <five times greater> (2) : equal fractional parts of which an indicated number equal a comparatively greater quantity <seven times smaller> <three times closer> c : TURN <three times at bat> 10 : finite as contrasted with infinite duration 11 : a person's experience during a specified period or on a particular occasion <a good time> <a hard time> 12 a : the hours or days required to be occupied by one's work <make up time> <on company time> b : an hourly pay rate <straight time> c : wages paid at discharge or resignation <pick up your time and get out> 13 a : the playing time of a game b : TIME-OUT 14 : a period during which something is used or available for use <computer time> - at the same time : NEVERTHELESS, YET <slick and at the same time strangely unprofessional -- Gerald Weaks> - at times : at intervals : OCCASIONALLY - for the time being : for the present - from time to time : once in a while : OCCASIONALLY - in no time : very quickly or soon - in time 1 : sufficiently early 2 : EVENTUALLY 3 : in correct tempo <learn to play in time> - on time 1 a : at the appointed time b : on schedule 2 : on the installment plan - time and again : FREQUENTLY, REPEATEDLY" source: http://www.m-w.com/dictionary/time

Movement of matter through space. Time came into existence after the singularity produced the "Big Bang".

From a science point of view time is that thing measured by a "clock". ... and a "clock" is anything that produces a regular count. Galileo used his heart beat - not amazingly accurate but still a form of "clock". Today the standard clock is based on the count of waves from light emitted by a transition between two energy levels in a cesium atom ... but the principle is the same. Two clocks can be calibrated to each other in the same way as two temperature scales. Einstein confused matters a little by noticing that other people's clocks don't necessarily run at the same rate as ours. The simple solution: always use your own clock.

http://en.wikipedia.org/wiki/Time Time is a component of a measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify the motions of objects. Time has been a major subject of religion, philosophy, and science, but defining time in a non-controversial manner applicable to all fields of study has consistently eluded the greatest scholars. In physics and other sciences, time is considered one of the few fundamental quantities. Time is used to define other quantities – such as velocity – and defining time in terms of such quantities would result in circularity of definition. An operational definition of time, wherein one says that observing a certain number of repetitions of one or another standard cyclical event (such as the passage of a free-swinging pendulum) constitutes one standard unit such as the second, has a high utility value in the conduct of both advanced experiments and everyday affairs of life. The operational definition leaves aside the question whether there is something called time, apart from the counting activity just mentioned, that flows and that can be measured. Investigations of a single continuum called space-time brings the nature of time into association with related questions into the nature of space, questions that have their roots in the works of early students of natural philosophy. Among prominent philosophers, there are two distinct viewpoints on time. One view is that time is part of the fundamental structure of the universe, a dimension in which events occur in sequence. Time travel, in this view, becomes a possibility as other "times" persist like frames of a film strip, spread out across the time line. Sir Isaac Newton subscribed to this realist view, and hence it is sometimes referred to as Newtonian time. The opposing view is that time does not refer to any kind of "container" that events and objects "move through", nor to any entity that "flows", but that it is instead part of a fundamental intellectual structure (together with space and number) within which humans sequence and compare events. This second view, in the tradition of Gottfried Leibniz and Immanuel Kant, holds that time is neither an event nor a thing, and thus is not itself measurable nor can it be traveled. Temporal measurement has occupied scientists and technologists, and was a prime motivation in navigation and astronomy. Periodic events and periodic motion have long served as standards for units of time. Examples include the apparent motion of the sun across the sky, the phases of the moon, the swing of a pendulum, and the beat of a heart. Currently, the international unit of time, the second, is defined in terms of radiation emitted by caesium atoms (see below). Time is also of significant social importance, having economic value ("time is money") as well as personal value, due to an awareness of the limited time in each day and in human lifespans.

Time is the continuous passage of existence from past through present to future. It is essentially a measure of change taking place among all objects in the universe occupying particular positions in space. It is also a measure of motion. For example, the earth rotates on its axis once every twenty-four hours and revolves around the sun once every three-hundred sixty-five days. If there were no change or motion, there would be no such thing as "time".

1) There is no widely accepted definition of time. One thing that is defined in relation to time is the second: "Under the International System of Units, the second is currently defined as The second is the duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom. This definition refers to a cesium atom at rest at a temperature of 0 K (absolute zero), and with appropriate corrections for gravitational time dilation. The ground state is defined at zero magnetic field. The second thus defined is consistent with the ephemeris second, which was based on astronomical measurements." Source and further information: http://en.wikipedia.org/wiki/Second Further information: http://en.wikipedia.org/wiki/Time 2) "We prove that for any (1 + 1)-dimensional globally hyperbolic space-time it is possible to define an instant of time as a special space-like geodesic which is independent of the coordinates chosen. This definition follows uniquely from the requirement of validity of Poincaré symmetry in an infinitesimal neighborhood of the hypersurface of instantaneity. The generator associated with time translation then selects the direction of time. This fact permits unambiguous field quantization of this surface. For flat space-time the corresponding time and vacuum coincide with those of Minkowski space-time. We apply these results to static and Robertson-Walker space-times." Source and further information: http://adsabs.harvard.edu/abs/1992MPLA....7.2317C 3) "Definition of time (noun) that which is measured in minutes, hours, days and years; a period that can be identified in hours and minutes and is shown on a clock; a period when an event should or will take place" Source and further information: http://pimsleur.english-test.net/definitions/definition-of-financial-own-origin-try-cold-time-green-snake-pardon-cancer.html 4) "Law on the definition of time (Zeitgesetz — ZeitG) 25 July 1978 last amended by law on 13 September 1994 (BGBl., Teil I, p. 2322) The German federal parliament has passed the following law: § 1 Legal time (1) In official and business communication, date and time are used according to legal time. (2) Legal time is Central European Time. It is defined as Coordinated Universal Time plus one hour. (3) Coordinated Universal Time is defined as a time scale with the following properties: On 1 January 1972, 0 hours, it corresponds to 31 December 1971, 23 hours, 59 minutes, 59.96 seconds mean solar time on the null meridian. The scale unit is the base unit second according to section 3 paragraph 4 of the law on units of measurement of 2 July 1969 (BGBl. I, p. 709), last amended by article 287 number 48 of the law of 2 March 1974 (BGBl. I, p. 469), at sea level. The time scale Coordinated Universal Time is kept in alignment with mean solar time at the null meridian with a tolerance of not more than one second, either by inserting one additional second or by omitting one second. (4) While in force, Central European Summer Time is legal time. It is defined as Coordinated Universal Time plus two hours. § 2 Representation and dissemination of legal time Legal time is represented and disseminated by the Federal Physics and Technology Agency [Physikalisch-Technische Bundesanstalt, PTB]. § 3 Authorization for introducing Central European Summer Time (1) The federal government is authorized, for better utilization of day light and for alignment of time keeping with neighbour countries, to introduce Central European Summer Time by decree for a time interval between 1 March and 31 October. (2) Central European Summer Time shall start and end on a Sunday, respectively. The federal government determines in the decree according to paragraph 1 the day and the time of day at which Central European Summer Time starts and ends, as well as the designation of the hour that appears twice at the end of Central European Summer Time. § 4 Other regulations § 9a of the aviation regulation as well as time regulations that result from the implementation of international treaties remain unaffected. § 5 Coming into force; replacement of other regulations This law comes into force at the day of publication. At the same time, the law regarding the introduction of a uniform time definition, published in BGBl. III, division number 7141-1, in revised form, goes out of force." Source and further information: "German Federal Law Journal (Bundesgesetzblatt, BGBl.), 1978, Part I, pp. 1110–1111" http://www.cl.cam.ac.uk/~mgk25/time/zeitgesetz.en.html German original: http://www.cl.cam.ac.uk/~mgk25/time/zeitgesetz.de.html 5) "Time concept is a very philosophical one since it is perceived differently by each person according to the activity that is taking place and even the state of mind. It reminds me of the basic dichotomy of perception-reality of philosophy that contributes so many discussions, many of which, in my opinion, are completely useless because they place themselves outside of natural logic or indicate a dead end in of themselves. Moreover, time concept is very much joined to life itself - it is hard to imagine life without the existence of time. Where would we find the origin of life in such a case? This concept of time could be defined as that which is understood by little children when they are so little that the world is “their world” and they orient time, which is why they think that when they sleep the world is immobile while it waits for them to wake, and that everything should be the same as when they went to bed. It is obvious that the subjective perception of physical time radically changes. When we are sleeping it is practically inexistent, only when we dream are we at all conscious of the passage of time, but normally we have no idea of how much time we have been in a particular dream. When we are awake, we also have a very variable perception of time. When we are really occupied it seems that time flies by; on the contrary, when we feel bored it feels as if time slows down. Another similar effect in relation to the speed of time is produced by the state of mind. It also seems that times goes by quickly if we are really happy, meanwhile, if we have a strong desire for an event in the near future to take place, it seems as if time stops, as if it were trying to go against us. In short, any activity, whether physical, mental or emotional, significantly affects the subjective perception of time, without us having the means to accurately measure its small variations." Source and further information: http://www.molwick.com/en/love/020-definition-second-meter.html#tiempo Further information: http://www.theorderoftime.com/spiritual/terms.html#time http://www.answerbag.com/q_view/1085793

now to now.

I don't have a clever answer to this question, just an interesting speculation. A line (1-d) is the representation of the movement of a point (0-d) over an interval. A square (2-d) is the representation of the movement of a line (1-d) over an interval. A cube (3-d) is the representation of the movement of a square (2-d) over an interval. Perhaps, whatever dimension you are considering, time is the next-higher dimension, in which movement occurs. Or, perhaps time is the movement itself.