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1. A tissue composed of fibers capable of contracting to effect bodily movement.
2. A contractile organ consisting of a special bundle of muscle tissue, which moves a particular bone, part, or substance of the body: the heart muscle; the muscles of the arm.
3. Muscular strength: enough muscle to be a high jumper.
4. Informal Power or authority: put some muscle into law enforcement.
v. mus·cled, mus·cling, mus·cles
To make one's way by or as if by force: muscled into the conversation.
To move or force with strength: muscled legislation through Congress.

[Middle English, from Old French, from Latin mūsculus, diminutive of mūs, mouse; see mūs- in Indo-European roots.]

mus′cly adj.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
References in classic literature ?
Powerfully muscled though some of them were, there had been something wrong with all of them, an insufficient development here, an undue development there, a twist or a crook that destroyed symmetry, legs too short or too long, or too much sinew or bone exposed, or too little.
Mighty and muscled as was the young giant, it yet would have appeared but the maddest folly for him to face so formidable a creature as Horta, the boar, armed only with a slender hunting knife.