Source : Webster's Revised Unabridged Dictionary (1913)

Period \Pe"ri*od\, v. t.
   To put an end to. [Obs.] --Shak.

Period \Pe"ri*od\, v. i.
   To come to a period; to conclude. [Obs.] ``You may period
   upon this, that,'' etc. --Felthman.

Period \Pe"ri*od\, n. [L. periodus, Gr. ? a going round, a way
   round, a circumference, a period of time; ? round, about + ?
   a way: cf. F. p['e]riode.]
   1. A portion of time as limited and determined by some
      recurring phenomenon, as by the completion of a revolution
      of one of the heavenly bodies; a division of time, as a
      series of years, months, or days, in which something is
      completed, and ready to recommence and go on in the same
      order; as, the period of the sun, or the earth, or a
      comet.

   2. Hence: A stated and recurring interval of time; more
      generally, an interval of time specified or left
      indefinite; a certain series of years, months, days, or
      the like; a time; a cycle; an age; an epoch; as, the
      period of the Roman republic.

            How by art to make plants more lasting than their
            ordinary period.                      --Bacon.

   3. (Geol.) One of the great divisions of geological time; as,
      the Tertiary period; the Glacial period. See the Chart of
      {Geology}.

   4. The termination or completion of a revolution, cycle,
      series of events, single event, or act; hence, a limit; a
      bound; an end; a conclusion. --Bacon.

            So spake the archangel Michael; then paused, As at
            the world's great period.             --Milton.

            Evils which shall never end till eternity hath a
            period.                               --Jer. Taylor.

            This is the period of my ambition.    --Shak.

   5. (Rhet.) A complete sentence, from one full stop to
      another; esp., a well-proportioned, harmonious sentence.
      ``Devolved his rounded periods.'' --Tennyson.

            Periods are beautiful when they are not too long.
                                                  --B. Johnson.

   Note: The period, according to Heyse, is a compound sentence
         consisting of a protasis and apodosis; according to
         Becker, it is the appropriate form for the
         co["o]rdinate propositions related by antithesis or
         causality. --Gibbs.

   6. (Print.) The punctuation point [.] that marks the end of a
      complete sentence, or of an abbreviated word.

   7. (Math.) One of several similar sets of figures or terms
      usually marked by points or commas placed at regular
      intervals, as in numeration, in the extraction of roots,
      and in circulating decimals.

Source : WordNet®

period
     n 1: an amount of time; "a time period of 30 years"; "hastened
          the period of time of his recovery"; "Picasso's blue
          period" [syn: {time period}, {period of time}]
     2: one of three periods of play in hockey games
     3: a stage in the history of a culture having a definable place
        in space and time; "a novel from the Victorian period"
        [syn: {historic period}, {historical period}]
     4: the interval taken to complete one cycle of a regularly
        repeating phenomenon
     5: the monthly discharge of blood from the uterus of
        nonpregnant women from puberty to menopause; "the women
        were sickly and subject to excessive menstruation"; "a
        woman does not take the gout unless her menses be
        stopped"--Hippocrates; "the semen begins to appear in
        males and to be emitted at the same time of life that the
        catamenia begin to flow in females"--Aristotle [syn: {menstruation},
         {menses}, {menstruum}, {catamenia}, {flow}]
     6: a punctuation mark (.) placed at the end of a declarative
        sentence to indicate a full stop or after abbreviations;
        "in England they call a period a stop" [syn: {point}, {full
        stop}, {stop}, {full point}]
     7: a unit of geological time during which a system of rocks
        formed; "ganoid fishes swarmed during the earlier
        geological periods" [syn: {geological period}]
     8: the end or completion of something; "death put a period to
        his endeavors"; "a change soon put a period to my
        tranquility"