The degree to which the muscles in a body part are developed.(noun)
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Use "muscularity" in a sentence
"Well, what about differences in muscularity and true fat?"
"It is a splendid combination, pluck and daring in their highest degree, with an unaffected and earnest regard to religion and religious duties, -- in short, muscularity with Christianity."
"Except for a certain muscularity, and a wonderful description of synesthesia toward the end, it’s […]"