1. Any of various cold-blooded, usually egg-laying vertebrates of the class Reptilia, such as a snake, lizard, crocodile, turtle, or dinosaur, having an external covering of scales or horny plates and breathing by means of lungs.
2. A person regarded as despicable or treacherous.

[Middle English reptil, from Old French reptile, from Late Latin rēptile, from neuter of Latin rēptilis, creeping, from rēptus, past participle of rēpere, to creep.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.