Definition from Wiktionary, the free dictionary
sidewinder (plural sidewinders)
- A North American rattlesnake, Crotalus cerastes, that inhabits lowland deserts.
- (slang) A person who is untrustworthy and dangerous.
- (slang, dated) A heavy swinging blow from the side which disables an adversary.
- (baseball, colloquial) A pitcher who throws sidearm.