colchicinePronunciation: /ˈkɒltʃɪsiːn, ˈkɒlk-/Definition of colchicine noun [mass noun] Chemistry a yellow compound present in the corms of colchicums, used to relieve pain in cases of gout. An alkaloid; chemical formula: C22H25NO6 colchicine in other Oxford dictionaries Definition of colchicine in the US English dictionary