diminution n. + Add to list US //ˌdɪməˈnuʃən// UK //dɪmɪnjˈuːʃən// diminu·tion SynonymsAntonymsEtymology Synonyms declinedecreasereductionstep down Antonyms augmentationincreaseOriginLATdīminūtiō→OFRdiminucion→XNOdiminuciun→MEdiminucioun→ENdiminution From Middle English diminucioun, from Anglo-Norman diminuciun, Old French diminucion, from Latin dīminūtiō.