/pear"ee euhd/ , n.
1. a rather large interval of time that is meaningful in the life of a person, in history, etc., because of its particular characteristics: a period of illness; a period of great profitability for a company; a period of social unrest in Germany.
2. any specified division or portion of time: poetry of the period from 1603 to 1660.
3. a round of time or series of years by which time is measured.
4. a round of time marked by the recurrence of some phenomenon or occupied by some recurring process or action.
5. the point of completion of a round of time or of the time during which something lasts or happens.
6. Educ. a specific length of time during school hours that a student spends in a classroom, laboratory, etc., or has free.
7. any of the parts of equal length into which a game is divided.
8. the time during which something runs its course.
9. the present time.
10. the point or character (.) used to mark the end of a declarative sentence, indicate an abbreviation, etc.; full stop.
11. a full pause, as is made at the end of a complete sentence; full stop.
12. a sentence, esp. a well-balanced, impressive sentence: the stately periods of Churchill.
13. a periodic sentence.
14. an occurrence of menstruation.
15. a time of the month during which menstruation occurs.
16. Geol. the basic unit of geologic time, during which a standard rock system is formed: comprising two or more epochs and included with other periods in an era. See table under geologic time .
17. Physics. the duration of one complete cycle of a wave or oscillation; the reciprocal of the frequency.
18. Music. a division of a composition, usually a passage of eight or sixteen measures, complete or satisfactory in itself, commonly consisting of two or more contrasted or complementary phrases ending with a conclusive cadence.
a. Also called period of rotation . the time in which a body rotates once on its axis.
b. Also called period of revolution . the time in which a planet or satellite revolves once about its primary.
20. Math. See under periodic (def. 5).
21. Class. Pros. a group of two or more cola.
22. noting, pertaining to, evocative of, imitating, or representing a historical period or the styles current during a specific period of history: period costumes; a period play.
23. (used by a speaker or writer to indicate that a decision is irrevocable or that a point is no longer discussable): I forbid you to go, period.
[ 1375-1425; late ME periode ( periodus, L períodos circuit, period of time, period in rhetoric, lit., way around. See PERI-, -ODE 2 ]
Syn. 1. See age. 2. term.