[ peer-ee-uhd ]
/ ˈpɪər i əd /



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.

Nearby words

  1. perineum,
  2. perineural anesthesia,
  3. perineuritis,
  4. perineurium,
  5. perinuclear,
  6. period drama,
  7. period of revolution,
  8. period piece,
  9. period-luminosity relation,
  10. periodate

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

Synonym study

1. See age.


[ peer-ee-od-ik ]
/ ˌpɪər iˈɒd ɪk /


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

British Dictionary definitions for period


/ (ˈpɪərɪəd) /


Word Origin for period

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


/ (ˌpɪərɪˈɒdɪk) /


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
Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for period


[ pîrē-əd ]


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.


[ pîr′ē-ŏdĭk ]


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


[ pĭrē-əd ]

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.