late 14c., "detriment, harm;" early 15c. as "a becoming less or smaller," from Anglo-French decres, from the verb (see decrease (v.)).
early 15c., decresen (intransitive) "become less, be diminished gradually," from Anglo-French decreiss-, present-participle stem of decreistre, Old French descroistre (12c., Modern French décroître), from Latin decrescere "to grow less, diminish," from de "away from" (see de-) + crescere "to grow" (from PIE root *ker- (2) "to grow"). Transitive sense of "make less, lessen" is from late 15c. Related: Decreased; decreasing.
Proto-Indo-European root meaning "to grow."
It forms all or part of: accretion; accrue; cereal; Ceres; concrete; create; creation; creature; Creole; crescendo; crescent; crew (n.) "group of soldiers;" croissant; cru; decrease; Dioscuri; excrescence; excrescent; griot; increase; Kore; procerity; procreate; procreation; recreate; recreation; recruit; sincere.
It is the hypothetical source of/evidence for its existence is provided by: Greek kouros "boy," korē "girl;" Latin crescere "come forth, spring up, grow, thrive, swell," Ceres, goddess of agriculture, creare "to bring forth, create, produce;" Armenian serem "bring forth," serim "be born."
mid-15c., "deterioration, decline in value, gradual loss of soundness or perfection," from decay (v.). Obsolete or archaic in reference to fortune or property; meaning "decomposition of organic tissue" is from 1590s. In physics, the meaning "gradual decrease in radioactivity" is by 1897.
c. 1400, decessioun, "departure, separation;" c. 1600, "decrease from a standard, diminution," from Latin decessionem(nominative decessio) "a going away, departure," noun of action from past-participle stem of decedere "to go down, depart," from de "away" (see de-) + cedere "to go" (from PIE root *ked- "to go, yield").
late 15c., "to decrease," also "to decline, deteriorate, lose strength or excellence," 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 "off" (see de-) + Latin cadere "to fall" (from PIE root *kad- "to fall").
Transitive sense of "cause to deteriorate, cause to become unsound or impaired" is from 1530s. Sense of "decompose, rot" is from 1570s. Related: Decayed; decaying.