What does muscle mean?
A muscle is one of the specialized tissues that enables the body to move, maintain its position, and carry out essential internal functions. In everyday use, the word also refers to physical strength or power, as in “show some muscle,” and more figuratively to forceful influence or leverage. “Muscle” can be used as a verb meaning to apply effort or pressure, especially in efforts to persuade, enforce, or secure a result. The term is common in both formal and informal contexts, ranging from medical discussion to political and organizational language. Its unusual history comes from the Latin musculus, literally “little mouse,” a comparison inspired by the way muscles bulge and move beneath the skin. Understanding this origin helps explain both the word’s vivid imagery and its long-standing use as a symbol of physical strength.
A tissue in the body that contracts and relaxes to produce movement, maintain posture, or perform an internal function.
"The muscle in his shoulder tightened after several hours of typing."
In medicine and anatomy, the term is precise. In general contexts, it may also mean physical strength or force.
To exert force, effort, or influence in order to achieve an objective.
"The local organizers muscled the proposal through the committee."
This use is informal and often suggests determined or forceful action.
Use “muscles” when referring to multiple anatomical muscles, or when describing physical strength or power.
"He worked out regularly to strengthen his muscles."
The word muscle comes from the Latin musculus, meaning “little mouse,” because muscles bulge and move beneath the skin like small animals.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does muscle come from?
The English word comes through Old French from Latin musculus, a diminutive of mus, meaning “mouse.” Latin musculus referred to a muscle, probably because of the way muscles resemble small moving animals under the skin. The same Latin root also underlies cognates such as mussel, whose Latin name musculus was applied to the shellfish because of its resemblance to a muscle.
Related word forms
How muscle is actually used
In its third sense, “muscle” is informal and often implies forceful or persuasive pressure. The singular “muscle” is common in idiomatic expressions such as “muscle memory,” while “muscles” is generally used when referring to strength or multiple anatomical muscles.
Easily confused with muscle
A muscle is a body tissue capable of contraction, whereas a mussel is a small marine shellfish.