1. Any of various venomous snakes of the family Viperidae, having a thick heavy body and a single pair of long hollow fangs, especially the Eurasian and African species of the subfamily Viperinae, which lack the sensory pits of the pit vipers.
2. Any of several harmless snakes sometimes believed to be venomous.
3. A person regarded as malicious or treacherous.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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