half-life

noun Date: 1907 1. the time required for half of something to undergo a process: as a. the time required for half of the atoms of a radioactive substance to become disintegrated b. the time required for half the amount of a substance (as a drug, radioactive tracer, or pesticide) in or introduced into a living system or ecosystem to be eliminated or disintegrated by natural processes 2. a period of usefulness or popularity preceding decline or obsolescence <

slang usually has a short half-life

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