Collins English-English Dictionary

period ['pɪərɪəd]

1. 1. n [Physics] [maths] the time taken to complete one cycle of a regularly recurring phenomenon; the reciprocal of frequency T

2. 2. n the punctuation mark (.) used at the end of a sentence that is not a question or exclamation, after abbreviations, etc full stop

3. 3. n [music] a passage or division of a piece of music, usually consisting of two or more contrasting or complementary musical phrases and ending on a cadence sentence

4. 4. n a portion of time of indefinable length

   he spent a period away from home

5. 5. n a portion of time specified in some way

   the Arthurian period

   Picasso's blue period

6. 6. n (as modifier)

   period costume

7. 7. n a nontechnical name for an occurrence of menstruation

8. 8. n [geology] a unit of geological time during which a system of rocks is formed

   the Jurassic period

9. 9. n a division of time, esp of the academic day

10. 10. n an interval in which the values of a periodic function follow a certain pattern that is duplicated over successive intervals

    sin x = sin (x + 2π), where 2π is the period

11. 11. n [Astronomy] the time required by a body to make one complete rotation on its axis

12. 12. n the time interval between two successive maxima or minima of light variation of a variable star

13. 13. n [chem] one of the horizontal rows of elements in the periodic table. Each period starts with an alkali metal and ends with a rare gas - Compare group

14. 14. n a complete sentence, esp a complex one with several clauses

15. 15. n (in classical prosody) a unit consisting of two or more cola

16. 16. n [rare] a completion or end

17. 17. n [Etymology] C14 peryod, from Latin periodus, from Greek periodos circuit, from peri- + hodos way