verb (used without object)
verb (used with object)
Origin of decay
Synonyms for decay
- (of an atomic nucleus) to undergo radioactive disintegration
- (of an elementary particle) to transform into two or more different elementary particles
- See radioactive decay
- a spontaneous transformation of an elementary particle into two or more different particles
- of an excited atom or molecule, losing energy by the spontaneous emission of photons
Word Origin for decay
mid-15c., "deterioration, decline in value," from decay (v.). Meaning "gradual decrease in radioactivity" is from 1897.
late 15c., "to decrease," from Anglo-French decair, Old North French decair (Old French decheoir, 12c., Modern French déchoir) "to fall, set (of the sun), weaken, decline, decay," from Vulgar Latin *decadere "to fall off," from de- (see de-) + Latin cadere "to fall" (see case (n.1)). Meaning "decline, deteriorate" is c.1500; that of "to decompose, rot" is from 1570s. Related: Decayed; decaying.