| Noun | 1. | genus Diadophis - a genus of reptiles of the family Colubridae including ringneck snakes reptile genus - a genus of reptiles Colubridae, family Colubridae - nonvenomous snakes; about two-thirds of all living species ringneck snake, ring-necked snake, ring snake - any of numerous small nonvenomous North American snakes with a yellow or orange ring around the neck |