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Meaning of EPOCH

Pronunciation:  'epuk

WordNet Dictionary
  1. [n]  a unit of geological time
  2. [n]  a period marked by distinctive character or reckoned from a fixed point or event
  3. [n]  (astronomy) the precise date that is the point of reference for which information (as coordinates of a celestial body) is referred

EPOCH is a 5 letter word that starts with E.


 Synonyms: date of reference, era
 See Also: age, Christian Era, Common Era, date, day, Eocene, Eocene epoch, geologic time, geological period, geological time, Glacial epoch, historic period, Holocene, Holocene epoch, Miocene, Miocene epoch, modern era, Oligocene, Oligocene epoch, Paleocene, Paleocene epoch, period, period of time, Pleistocene, Pleistocene epoch, Pliocene, Pliocene epoch, Recent epoch, time period



Webster's 1913 Dictionary
\Ep"och\ (?; 277), n. [LL. epocha, Gr. ? check, stop, an
epoch of a star, an historical epoch, fr. ? to hold on,
check; 'epi` upon + ? to have, hold; akin to Skr. sah to
overpower, Goth. sigis victory, AS. sigor, sige, G. sieg: cf.
F. ['e]poque. See {Scheme}.]
1. A fixed point of time, established in history by the
   occurrence of some grand or remarkable event; a point of
   time marked by an event of great subsequent influence; as,
   the epoch of the creation; the birth of Christ was the
   epoch which gave rise to the Christian era.

         In divers ages, . . . divers epochs of time were
         used.                                 --Usher.

         Great epochs and crises in the kingdom of God.

         The acquittal of the bishops was not the only event
         which makes the 30th of June, 1688, a great epoch in
         history.                              --Macaulay.

Note: Epochs mark the beginning of new historical periods,
      and dates are often numbered from them.

2. A period of time, longer or shorter, remarkable for events
   of great subsequent influence; a memorable period; as, the
   epoch of maritime discovery, or of the Reformation. ``So
   vast an epoch of time.'' --F. Harrison.

         The influence of Chaucer continued to live even
         during the dreary interval which separates from one
         another two important epochs of our literary
         history.                              --A. W. Ward.

3. (Geol.) A division of time characterized by the prevalence
   of similar conditions of the earth; commonly a minor
   division or part of a period.

         The long geological epoch which stored up the vast
         coal measures.                        --J. C.

4. (Astron.)
   (a) The date at which a planet or comet has a longitude or
   (b) An arbitrary fixed date, for which the elements used
       in computing the place of a planet, or other heavenly
       body, at any other date, are given; as, the epoch of
       Mars; lunar elements for the epoch March 1st, 1860.

Syn: Era; time; date; period; age.

Usage: {Epoch}, {Era}. We speak of the era of the
       Reformation, when we think of it as a period, during
       which a new order of things prevailed; so also, the
       era of good feeling, etc. Had we been thinking of the
       time as marked by certain great events, or as a period
       in which great results were effected, we should have
       called the times when these events happened epochs,
       and the whole period an epoch.

             The capture of Constantinople is an epoch in the
             history of Mahometanism; but the flight of
             Mahomet is its era.               --C. J. Smith.

Computing Dictionary

1. [Unix: probably from astronomical timekeeping] The time and date corresponding to 0 in an operating system's clock and timestamp values. Under most Unix versions the epoch is 00:00:00 GMT, January 1, 1970; under VMS, it's 00:00:00 of November 17, 1858 (base date of the US Naval Observatory's ephemerides); on a Macintosh, it's the midnight beginning January 1 1904. System time is measured in seconds or ticks past the epoch. Weird problems may ensue when the clock wraps around (see wrap around), which is not necessarily a rare event; on systems counting 10 ticks per second, a signed 32-bit count of ticks is good only for 6.8 years. The 1-tick-per-second clock of Unix is good only until January 18, 2038, assuming at least some software continues to consider it signed and that word lengths don't increase by then. See also wall time.

2. (Epoch) A version of gnu emacs for the x window system from ncsa.

[jargon file]

 Definition: a unit of geological time; a division of a period.
Thesaurus Terms
 Related Terms: age, Bronze Age, Dark Ages, days, Depression Era, era, glacial epoch, Golden Age, Ice Age, interval, Iron Age, Jacksonian Age, Middle Ages, New Deal Era, Prohibition Era, Silver Age, Steel Age, Stone Age, term, time