the length of time something continues or exists (often used with the ).
2.
continuance in time.
3.
(in the philosophy of Bergson) a temporal continuum, intuitively known, within which the élan vital operates.
Origin: 1350–1400;Middle English < Medieval Latindūrātiōn- (stem of dūrātiō), equivalent to Latindūrāt(us) (past participle of dūrāre to last; see dure2) + -iōn--ion
late 14c., from O.Fr. duration, from M.L. durationem (nom. duratio), from L. durare "harden" (see endure). Phrase for the duration (1916) originally refers to British enlistment in World War I.