ageing UK/ˈeɪd͡ʒɪŋ/ uncommon noun (2) adjective (1) noun 1. acquiring desirable qualities by being left undisturbed for some time Synonymsripeningaging 2. the organic process of growing older and showing the effects of increasing age Synonymsagingsenescence adjective 1. growing old Synonymsagingsenescent Similarold Related words Broader terms organic process Narrower terms catabiosismellowing WordNet 2.1 (Princeton University). Wiktionary (CC BY-SA). WordNet 2.1 Copyright Princeton University. All rights reserved.