a large, poisonous, olive-brown
pit viper (Agkistrodon piscivorus
) with dark crossbars
, found along or in rivers and swamps in the SE U.S.; cottonmouth: often confused
with various harmless
snakes, esp. several water snakes (genus Natrix
Webster’s New World College Dictionary, 4th Edition. Copyright © 2010 by
Houghton Mifflin Harcourt. All rights reserved.