Period

Common uses

Period (punctuation)
Era, length or span of time
- Periodization, classifying particular lengths of time into distinct historiographic or artistic periods
- List of time periods
- History by period
Menstruation, commonly referred to as a "period"

In a repeating decimal, the length of the repetend
Period of a function, length or duration after which a function repeats itself
Period (algebraic geometry), numbers that can be expressed as integrals of algebraic differential forms over algebraically defined domains, forming a ring

Period (gene), gene in Drosophila involved in regulating circadian rhythm
Period (periodic table), horizontal row of the periodic table
"Period-" or "per-iod-", chemical prefix where "per" refers to oxidation state and "iod" refers to iodine
Unit of time or timeframe
- Period (geology), 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 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

Period (school), block of time allocated for a specific course or other purpose
Playing period, a division of playing time in games and sport
- Period (ice hockey)
Accounting period, often shortened to "period" in business, an accounting timeframe analogous to a month
Periodt, slang of period used as an interjection