inky cap in·ky·cap uncommon noun 1. having a cap that melts into an inky fluid after spores have matured Synonymsinky capinky-cap mushroomCoprinus atramentarius Related words Word family inky-cap mushroom Broader terms agaric Parts Coprinus WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.
