sidewinder

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A small rattlesnake (Crotalus cerastes) of the southwest United States and Mexico that moves by a distinctive lateral looping motion of its body and has a hornlike scaly projection above each eye.
• noun A powerful swinging punch delivered from the side.

from The Century Dictionary.

• noun In lumbering, a tree knocked down unexpectedly by the falling of another.
• noun The small horned rattler or rattlesnake of the southwestern parts of the United States, Crotalus (Æchmophrys) cerastes.
• noun A heavy swinging blow from the side, which disables an adversary.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Zoöl.) See Horned rattler, under horned.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A North American rattlesnake, Crotalus cerastes, that inhabits lowland deserts.
• noun slang A person who is untrustworthy and dangerous.
• noun slang, dated A heavy swinging blow from the side which disables an adversary.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun small pale-colored desert rattlesnake of southwestern United States; body moves in an s-shaped curve
• noun air-to-air missile with infrared homing device