Period

Period may mean a full stop: a punctuation in American-English.

Period (from Greek περίοδος) or periodic may also refer to:

Science

• Orbital period, a concept in astronomy
• Period (gene), a gene in Drosophila involved in regulating circadian rhythm
• Period (geology), a subdivision of geologic time
• Periodic function and periodical, a function that repeats its values in regular intervals
• Periodic group in group theory
• Periodic table, a chart which lists all currently known chemical elements

• Period (periodic table), a horizontal row of the periodic table

• Periodic acid, an oxoacid of iodine
• Period (physics), the time taken for one full oscillation, it is the reciprocal of frequency
• Period of orbit
• Period of time
• Period | also known as menstrual cycle

Language and literature

• Period (punctuation), a punctuation mark indicating the end of a sentence or phrase, specifically, a dot.
• Periodic sentence, a sentence that is not grammatically complete until its end
• The final book in Dennis Cooper's George Miles cycle of novels

History

• Period piece describes creative works set in a particular era

Medical

• Menstruation, a phase of the menstrual cycle in which the uterine lining is shed

Mathematics

• The period of a periodic function
• Periods (ring) — the ring of numbers which can be expressed as integrals of algebraic differential forms over algebraically defined domains
• Pisano period

Academics

• Period (school), a class period in schools

Music / Instruments

• Period (music), a concept in musical composition

Sports

• Periods in ice hockey, intervals into which a match is divided

Other meanings

• Periodicity, the quality of occurring at regular intervals or periods

See also

• Periodization
• Full stop (disambiguation)