Period may refer to:
Common uses
*
Era
An era is a span of time defined for the purposes of chronology or historiography, as in the regnal eras in the history of a given monarchy, a calendar era used for a given calendar, or the geological eras defined for the history of Earth.
Compa ...
, a length or span of time
*
Full stop
The full stop (Commonwealth English), period (North American English), or full point , is a punctuation mark. It is used for several purposes, most often to mark the end of a declarative sentence (as distinguished from a question or exclamation ...
(or period), a punctuation mark
Arts, entertainment, and media
*
Period (music), a concept in musical composition
*
Periodic sentence A periodic sentence is a sentence with a stylistic device featuring syntactical subordination to a single main idea, which usually is not complete until the very end of the sentence. The periodic sentence emphasizes its main idea by placing it at ...
(or rhetorical period), a concept in grammar and literary style.
* Period, a descriptor for a historical or
period drama
* Period, a timeframe in which a particular style of
antique furniture or some other work of art was produced, such as the "Edwardian period"
* ''
Period (Another American Lie)
''Period (Another American Lie)'' is the debut studio album by B.A.L.L., released in 1987 by Shimmy Disc.
Track listing
Personnel
Adapted from the ''Period (Another American Lie)'' liner notes.
;B.A.L.L.
* Don Fleming – vocals, g ...
'', a 1987 album by B.A.L.L.
*
''Period'' (mixtape), a 2018 mixtape by City Girls
* ''Period'', the final book in Dennis Cooper's
George Miles cycle of novels
Mathematics
* In a
repeating decimal, the length of the repetend
*
Period of a function
A periodic function is a function that repeats its values at regular intervals. For example, the trigonometric functions, which repeat at intervals of 2\pi radians, are periodic functions. Periodic functions are used throughout science to desc ...
, length or duration after which a function repeats itself
*
Period (algebraic geometry)
In algebraic geometry, a period is a number that can be expressed as an integral of an algebraic function over an algebraic domain. Sums and products of periods remain periods, so the periods form a ring.
Maxim Kontsevich and Don Zagier gav ...
, numbers that can be expressed as integrals of algebraic differential forms over algebraically defined domains, forming a ring
Science
*
Period (gene)
Period (per) is a gene located on the X chromosome of ''Drosophila melanogaster''. Oscillations in levels of both ''per'' transcript and its corresponding protein PER have a period of approximately 24 hours and together play a central role in the ...
, a gene in ''Drosophila'' involved in regulating circadian rhythm
*
Period (periodic table), a horizontal row of the periodic table
* "Period-" or "per-iod-", in some chemical compounds, "per" refers to oxidation state, and "iod" refers to the compound containing
iodine
Iodine is a chemical element with the symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a semi-lustrous, non-metallic solid at standard conditions that melts to form a deep violet liquid at , and boils to a vi ...
*
Menstruation
Menstruation (also known as a period, among other colloquial terms) is the regular discharge of blood and mucosal tissue from the inner lining of the uterus through the vagina. The menstrual cycle is characterized by the rise and fall of hor ...
, also called a "period"
*
Unit of time or timeframe
**
Period (geology)
The geologic time scale, or geological time scale, (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochrono ...
, a subdivision of geologic time
**
Period (physics), the duration of time of one cycle in a repeating event
**
Orbital period, the time needed for one object to complete an orbit around another
**
Rotation period
The rotation period of a celestial object (e.g., star, gas giant, planet, moon, asteroid) may refer to its sidereal rotation period, i.e. the time that the object takes to complete a single revolution around its axis of rotation relative to the ...
, the time needed for one object to complete a revolution
*
Wavelength, the spatial period of a periodic wave
*
Sentence (linguistics), especially when discussing complex sentences in Latin syntax
Other uses
*
Period (school), a class meeting time in schools
*
Period (ice hockey), a division of play in an ice hockey game
*
Accounting period, often shortened to "period" in business, an accounting timeframe analogous to a month
See also
*
Duration (disambiguation)
*
Full stop (disambiguation)
*
Periodicity (disambiguation)
*
Periodization
*
List of time periods
*
History by period
{{disambiguation