Origin: Latin suffix -ular
Muscular has 5 different meanings across 1 category:
having a robust muscular body-build characterized by predominance of structures (bone and muscle and connective tissue) developed from the embryonic mesodermal layer
"The athlete's muscular physique displayed a robust build where bone, muscle, and connective tissue had all been powerfully developed from the embryonic mesoderm."
having or suggesting great physical power or force
"the muscular and passionate Fifth Symphony"
Of, relating to, or connected with muscles.
"The muscular strain in his back made it difficult for him to lift the heavy box."
In plain English: Muscular means having strong and well-developed muscles that look big and fit.
"The football player has very strong and muscular arms."
Usage: Use muscular to describe physical strength and development in people or animals rather than abstract concepts like power. Avoid confusing it with the adjective powerful when referring specifically to visible muscle tone.
The word muscular appeared in the late 17th century by adding the suffix "-ar" to "muscle," which itself comes from the Latin mūsculus. It entered English through a similar formation found in French, describing anything related to muscles.