duration

n. period of time that something continues

For other meanings of duration, see Duration (disambiguation). A duration is an amount of time or a particular time interval. For example, an event in the common sense has a duration greater than zero (but not very long), but in certain specialized senses (such as in the theory of relativity), a duration of zero. It is often cited as one of the fundamental aspects of music, see also rhythm.
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Noun
1. the period of time during which something continues
(synonym) continuance
(hypernym) time period, period of time, period
(hyponym) clocking
2. the property of enduring or continuing in time
(synonym) continuance
(hypernym) time
3. continuance in time; "the ceremony was of short duration"; "he complained about the length of time required"
(synonym) length
(hypernym) temporal property
(hyponym) longness
(attribute) long

(n.)
The state or quality of lasting; continuance in time; the portion of time during which anything exists.
  

Duration As used in theosophy, clearly distinguished from time. Duration is; it has neither beginning nor end, nor is it broken up into cyclic periods as time is. Time may be called its representation in the manifested universe, and therefore time is finite. Duration is outside of both manifested time and space; it is here that the distinction between time and space, both being manifestations, may be said to disappear, and we may say that abstract space and duration are one. Thus boundless duration divides into what may be called eternal, universal, unconditioned time and a conditioned time -- the former the noumenon and the latter phenomenon.