n.
         - a length or portion of time. ▸a major division of geological time that is a subdivision of an era and is itself subdivided into epochs. 
- each of the set divisions of the day in a school.
- 
(also menstrual period)
 a monthly flow of blood and other material from the lining of the uterus, occurring in women of childbearing age when not pregnant.
- N. Amer. a full stop.
- Physics  the interval of time between successive occurrences of the same state in an oscillatory or cyclic phenomenon.
- Mathematics  the interval between successive equal values of a periodic function.
- Chemistry  a set of elements occupying a horizontal row in the periodic table.
- Astronomy  the time taken by a celestial object to rotate about its axis, or to make one circuit of its orbit.
- Rhetoric  a complex sentence, especially one consisting of several clauses, constructed as part of a formal speech or oration.
adj.
 belonging to or characteristic in style of a past historical time:
![]() 
 period furniture.
Derivative
  
    - periodization
 or periodisation n.
- periodize
 or periodise v.
 
  Etymology
  ME: from OFr. periode, via L. from Gk periodos ‘orbit, recurrence, course’.