n. & adj.
n. 1 a length or portion of time (showers and bright periods). 2 a distinct portion of history, a person's life, etc. (the Georgian period; Picasso's Blue Period). 3 Geol. a time forming part of a geological era (the Quaternary period). 4 a an interval between recurrences of an astronomical or other phenomenon. b the time taken by a planet to rotate about its axis. 5 the time allowed for a lesson in school. 6 an occurrence of menstruation. 7 a a complete sentence, esp. one consisting of several clauses. b (in pl.) rhetorical language. 8 esp. US a = full stop (see FULL(1)). b used at the end of a sentence etc. to indicate finality, absoluteness, etc. (we want the best, period). 9 a a set of figures marked off in a large number to assist in reading. b a set of figures repeated in a recurring decimal. c the smallest interval over which a function takes the same value. 10 Chem. a sequence of elements between two noble gases forming a row in the periodic table.
adj. belonging to or characteristic of some past period (period furniture). of the period of the era under discussion (the custom of the period). period piece an object or work whose main interest lies in its historical etc. associations.
[ ME f. OF periode f. L periodus f. Gk periodos (as PERI-, odos = hodos way) ]