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noun pe·ri·od \ˈpir-ē-əd\

Simple Definition of period

  • : a length of time during which a series of events or an action takes place or is completed

  • : a length of time that is very important in the history of the world, a nation, etc.

  • : a time that is very important in the life of a person

Source: Merriam-Webster's Learner's Dictionary

Full Definition of period

  1. 1 :  the completion of a cycle, a series of events, or a single action :  conclusion

  2. 2 a (1) :  an utterance from one full stop to another :  sentence (2) :  a well-proportioned sentence of several clauses (3) :  periodic sentence b :  a musical structure or melodic section usually composed of two or more contrasting or complementary phrases and ending with a cadence

  3. 3 a :  the full pause with which the utterance of a sentence closes b :  end, stop

  4. 4 obsolete :  goal, purpose

  5. 5 a (1) :  a point . used to mark the end (as of a declarative sentence or an abbreviation) (2) —used interjectionally to emphasize the finality of the preceding statement <I don't remember — period> b :  a rhythmical unit in Greek verse composed of a series of two or more cola

  6. 6 a :  a portion of time determined by some recurring phenomenon b (1) :  the interval of time required for a cyclic motion or phenomenon to complete a cycle and begin to repeat itself (2) :  a number k that does not change the value of a periodic function f when added to the independent variable; especially :  the smallest such number c :  a single cyclic occurrence of menstruation

  7. 7 a :  a chronological division :  stage b :  a division of geologic time longer than an epoch and included in an era c :  a stage of culture having a definable place in time and space

  8. 8 a :  one of the divisions of the academic day b :  one of the divisions of the playing time of a game

Examples of period in a sentence

  1. We have had two power failures in a five-month period.

  2. The period between Christmas and New Year's Eve is a very busy one for us.

  3. We are studying our country's colonial period.

  4. Children go through many changes during the period of adolescence.

Origin and Etymology of period

Middle English periode, from Middle French, from Medieval Latin, Latin, & Greek; Medieval Latin periodus period of time, punctuation mark, from Latin & Greek; Latin, rhetorical period, from Greek periodos circuit, period of time, rhetorical period, from peri- + hodos way

First Known Use: circa 1530

Synonym Discussion of period

period, epoch, era, age mean a division of time. period may designate an extent of time of any length <periods of economic prosperity>. epoch applies to a period begun or set off by some significant or striking quality, change, or series of events <the steam engine marked a new epoch in industry>. era suggests a period of history marked by a new or distinct order of things <the era of global communications>. age is used frequently of a fairly definite period dominated by a prominent figure or feature <the age of Samuel Johnson>.



adjective pe·ri·od

Simple Definition of period

  • : of, relating to, or typical of a particular time in history

Source: Merriam-Webster's Learner's Dictionary

Full Definition of period

  1. :  of, relating to, or representing a particular historical period <period furniture> <period costumes>


First Known Use of period


PERIOD Defined for Kids


noun pe·ri·od \ˈpir-ē-əd\

Definition of period for Students

  1. 1 :  a punctuation mark . used chiefly to mark the end of a declarative sentence or an abbreviation

  2. 2 :  a portion of time set apart by some quality <a period of cool weather>

  3. 3 :  a portion of time that forms a stage in history <the colonial period>

  4. 4 :  one of the divisions of a school day <I have math second period.>

  5. 5 :  a single occurrence of menstruation

Medical Dictionary


noun pe·ri·od \ˈpir-ē-əd\

Medical Definition of period

  1. 1a:  a portion of time determined by some recurring phenomenonb:  a single cyclic occurrence of menstruation

  2. 2:  a chronological division <the period of incubation of a disease>

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