(historical) The Uruk period.

(historical) A period between circa 4000 to 3100 BC which saw the emergence of urban life in Mesopotamia and the Sumerian civilization.

(idiomatic, slang, euphemistic) Menstruating.

plural of period drama

(accounting) A system of assessing a business' inventory in which updates are made on a periodic basis, so that a completely accurate account is only available immediately after the update.

Alternative form of periodic comet

Alternative spelling of quasiperiodic

A period during which a telecommunications service remains in an operational state.

(psychology) A delay to the second response to two closely-spaced stimuli

A length of time in which the two sides to a purchase agreement, or contract can think things over and cancel with no penalty. This period is often stipulated by national law. In the UK it is currently (2008) 14 days. In many countries it is 10 days.