period

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. An interval of time characterized by the occurrence of a certain condition, event, or phenomenon: a period of economic prosperity.
2. n. An interval of time characterized by the prevalence of a specified culture, ideology, or technology: artifacts of the pre-Columbian period.
3. n. An interval regarded as a distinct evolutionary or developmental phase: Picasso's early career is divided into his blue period and rose period.
4. n. Geology A unit of time, longer than an epoch and shorter than an era.
5. n. Any of various arbitrary units of time, especially:
6. n. Any of the divisions of the academic day.
7. n. Sports & Games A division of the playing time of a game.
8. n. Physics & Astronomy The time interval between two successive occurrences of a recurrent event or phases of an event; a cycle: the period of a satellite's orbit.
9. n. An instance or occurrence of menstruation.
10. n. A point or portion of time at which something is ended; a completion or conclusion.
11. n. The full pause at the end of a spoken sentence.
12. n. A punctuation mark ( . ) indicating a full stop, placed at the end of declarative sentences and other statements thought to be complete, and after many abbreviations.
13. n. A sentence of several carefully balanced clauses in formal writing.
14. n. A metrical unit of quantitative verse consisting of two or more cola.
15. n. An analogous unit or division of classical Greek or Latin prose.
16. n. Music A group of two or more phrases within a composition, often made up of 8 or 16 measures and terminating with a cadence.
17. n. Mathematics The least interval in the range of the independent variable of a periodic function of a real variable in which all possible values of the dependent variable are assumed.
18. n. Mathematics A group of digits separated by commas in a written number.
19. n. Mathematics The number of digits that repeat in a repeating decimal. For example, ¹/₇ = 0.142857142857 . . . has a six-digit period.
20. n. Chemistry A sequence of elements arranged in order of increasing atomic number and forming one of the horizontal rows in the periodic table.
21. adj. Of, belonging to, or representing a certain historical age or time: a period piece; period furniture.
22. interj. Used to emphasize finality, as when expressing a decision or an opinion: You're not going to the movies tonight, period!

Century Dictionary and Cyclopedia

1. n. A circuit: a round; hence, the time in which a circuit or revolution, as of a heavenly body, is made; the shortest interval of time within which any phenomenon goes through its changes of pass through them again immediately as before.
2. n. Any round of time, or series of years, days, etc. Specifically— A revolution or series of years by which time is measured; a cycle: as, the Calippic period; the Dionysian period; the Julian period.
3. n. An indefinite part of any continued state, existence, or series of events; an epoch: as, the first period of life; the last period of a king's reign; the period of the French revolution.
4. n. The point of completion of a cycle of years or round or series of events; limit; end; conclusion; termination.
5. n. Hence— The end to be attained; goal.
6. n. In rhetoric, a complete sentence from one full stop to another; a passage terminated by a full pause.
7. n. In ancient prosody, a group of two or more cola. According to the number of cola it contains, a period is dicolic, tricolic, tetracolic, etc. The end (apothesis) of a period must coincide with the end of a word, and is also characterzied by admitting of syllaba anceps and hiatus. A single colon treated thus is also regarded as a period (a monocolic period). A monocolic, dicolic, etc., period is a meter. (See meter, 1 .) Certain periods are known as lines or verses. (See line, 6 .) A group of periods is called a system.
8. n. In music, a definite and complete division of a composition, usually consisting of two or more contrasted or complementary phrases; a complete musical sentence. The term is somewhat variously used; but it always involves a cadence at the end of the period, by which it is distinctly separated from what follows. Usually a period includes eight or sixteen measures.
9. n. The point or character that marks the end of a complete sentence, or indicates an abbreviation, etc.; a full stop, thus(.).
10. n. In math.: The smallest constant difference which, added to the value of a variable, will leave that of a function (of which it is said to be the period) unchanged.
11. n. In vulgar arithmetic, one of several similar sets of figures or terms, marked by points or commas placed regularly after a certain number, as in numeration, in circulating decimals, and in the extraction of roots. Sometimes called degree.
12. n. In medicine, one of the phases or epochs which are distinguishable in the course of a disease.
13. n. Duration, continuance, term.
14. n. Bound, determination.
15. To put an end to.
16. To end; cease.
17. n. plural The menses.
18. n. In physical, the time of one complete oscillation or cycle of a periodic motion; the reciprocal of the frequency of a periodic motion.
19. n. In astronomy, the time of the revolution of a planet or satellite around its primary. Also orbital period.
20. n. In geology, technically, one of the larger divisions of geologic time of either the second or the third order, measured by the time of deposition of a ‘group’ or ‘system’ of formations, and characterized by the presence of a number of allied and similar faunas which as a whole differ from those of other periods. In Dana's classification the berm is applied to the third order of time-division, while the more generally adopted scheme of the International Geological Congress accords it second rank. The relation between the two a sages of this and other terms of time-nomenclature and the correlated structural and faunal equivalents is shown in the following table:

Wiktionary

1. adj. Appropriate for a given historical era.
2. adj. of a film Set in and designed to evoke a particular historical period, especially through the use of elaborate costumes and scenery.
3. interj. And nothing else; and nothing less; used for emphasis.
4. n. The punctuation mark “.” (indicating the ending of a sentence or marking an abbreviation).
5. n. genetics A Drosophila gene which gene product is involved in regulation of the circadian rhythm
6. n. music two phrases (an antecedent and a consequent phrase)
7. v. obsolete, intransitive To come to a period; to conclude.

GNU Webster's 1913

1. n. 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.
2. n. 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.
3. n. (Geol.) One of the great divisions of geological time. See the Chart of Geology.
4. n. The termination or completion of a revolution, cycle, series of events, single event, or act; hence, a limit; a bound; an end; a conclusion.
5. n. (Rhet.) A complete sentence, from one full stop to another; esp., a well-proportioned, harmonious sentence.
6. n. (Print.) The punctuation point [.] that marks the end of a complete sentence, or of an abbreviated word.
7. n. (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.
8. n. (Med.) The time of the exacerbation and remission of a disease, or of the paroxysm and intermission.
9. n. (Mus.) A complete musical sentence.
10. v. obsolete To put an end to.
11. v. To come to a period; to conclude. [Obs.] “You may period upon this, that,” etc.

WordNet 3.0

1. n. a unit of geological time during which a system of rocks formed
2. n. (ice hockey) one of three divisions into which play is divided in hockey games
3. n. a punctuation mark (.) placed at the end of a declarative sentence to indicate a full stop or after abbreviations
4. n. an amount of time
5. n. the interval taken to complete one cycle of a regularly repeating phenomenon
6. n. the end or completion of something
7. n. the monthly discharge of blood from the uterus of nonpregnant women from puberty to menopause