Definitions
1.NounA water mocassin (Agkistrodon piscivorus), a venomous aquatic snake of North America.
2.NounAny of species Natrix natrix of non-venomous European sbakes.
3.NounAny aquatic snake, such as:
4.NounA northern water snake (Nerodia sipedon), a non-venomous American snake.
5.Noun(Can we verify this sense?) A crab-eating water snake or white-bellied mangrove snake (Fordonia leucobalia), a venomous snake of south Asia.
6.NounUsed other than figuratively or idiomatically: see water, adder.