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.


(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.

Origin of period

1375–1425; late Middle English periode (< Middle French) < Medieval Latin periodus, Latin < Greek períodos circuit, period of time, period in rhetoric, literally, way around. See peri-, -ode2
Related formssub·pe·ri·od, noun
Can be confusedinterval period

Synonyms for period

2. term.

Synonym study

1. See age.




recurring at intervals of time: periodic revivals of an interest in handicrafts.
occurring or appearing at regular intervals: periodic visits by doctors to the village.
repeated at irregular intervals; intermittent: periodic outbreaks of the disease.
Physics. recurring at equal intervals of time.
Mathematics. (of a function) having a graph that repeats after a fixed interval (period) of the independent variable.
  1. characterized by a series of successive circuits or revolutions, as the motion of a planet or satellite.
  2. of or relating to a period, as of the revolution of a heavenly body.
pertaining to or characterized by rhetorical periods, or periodic sentences.

Origin of periodic

1635–45; < Latin periodicus < Greek periodikós. See period, -ic
Related formspe·ri·od·i·cal·ly, adverbqua·si-pe·ri·od·i·cal·ly, adverb
Can be confusedperiodic periodical Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for period

Contemporary Examples of period

Historical Examples of period

British Dictionary definitions for period



a portion of time of indefinable lengthhe spent a period away from home
  1. a portion of time specified in some waythe Arthurian period; Picasso's blue period
  2. (as modifier)period costume
a nontechnical name for an occurrence of menstruation
geology a unit of geological time during which a system of rocks is formedthe Jurassic period
a division of time, esp of the academic day
physics maths
  1. the time taken to complete one cycle of a regularly recurring phenomenon; the reciprocal of frequencySymbol: T
  2. an interval in which the values of a periodic function follow a certain pattern that is duplicated over successive intervalssin x = sin ( x + 2π ), where 2π is the period
  1. the time required by a body to make one complete rotation on its axis
  2. the time interval between two successive maxima or minima of light variation of a variable star
chem one of the horizontal rows of elements in the periodic table. Each period starts with an alkali metal and ends with a rare gasCompare group (def. 11)
Also called: full stop the punctuation mark (.) used at the end of a sentence that is not a question or exclamation, after abbreviations, etc
a complete sentence, esp a complex one with several clauses
Also called: sentence music a passage or division of a piece of music, usually consisting of two or more contrasting or complementary musical phrases and ending on a cadence
(in classical prosody) a unit consisting of two or more cola
rare a completion or end

Word Origin for period

C14 peryod, from Latin periodus, from Greek periodos circuit, from peri- + hodos way



happening or recurring at intervals; intermittent
of, relating to, or resembling a period
having or occurring in repeated periods or cycles
Derived Formsperiodically, adverbperiodicity (ˌpɪərɪəˈdɪsɪtɪ), noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for period

early 15c., "course or extent of time," from Middle French periode (14c.) and directly from Medieval Latin periodus "recurring portion, cycle," from Latin periodus "a complete sentence," also "cycle of the Greek games," from Greek periodos "cycle, circuit, period of time," literally "a going around," from peri- "around" (see peri-) + hodos "a going, way, journey" (see cede).

Sense of "repeated cycle of events" led to that of "interval of time." Meaning "dot marking end of a sentence" first recorded c.1600, from similar use in Medieval Latin (in late 16c. English it meant "full pause at the end of a sentence"). Sense of "menstruation" dates from 1822. Educational sense of "portion of time set apart for a lesson" is from 1876. Sporting sense attested from 1898. As an adjective from 1905; period piece attested from 1911.



1640s, from French périodique (14c.), from Latin periodicus, from periodus (see period).

Periodic table in chemistry (1889) is from notion of the arrangement, in which similar properties recur at intervals in elements in the same area as you read down the rows of the table. This sense of the word is attested from 1872 (periodic law).

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for period




An interval of time characterized by the occurrence of a certain condition, event, or phenomenon.
One of the stages of a disease.
A menstrual period.
A sequence of elements arranged in order of increasing atomic number.




Having or marked by repeated cycles.
Recurring at regular intervals.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for period



A division of geologic time that is longer than an epoch and shorter than an era.
The duration of one cycle of a regularly recurring action or event. See also cycle frequency.
An occurrence of menstruation.
In the Periodic Table, any of the seven horizontal rows that contain elements arranged in order of increasing atomic number. All the elements in a particular period have the same number of electron shells in their atoms, equal to the number of the period. Thus, atoms of nickel, copper, and zinc, in period four, each have four electron shells. See Periodic Table.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Culture definitions for period


A punctuation mark (.) that ends a declarative sentence. A period is also used in abbreviations such as Mr. and Dr.

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.