muscularity vs sinew

muscularity and sinew both are nouns.

Word	Noun	Adjective	Verb	Adverb
muscularity	Yes	No	No	No
sinew	Yes	No	No	No

As nouns, muscularity and sinew are synonyms defined as:

Other synonyms of muscularity include brawn, brawniness, heftiness, muscle.

muscularity (noun)	sinew (noun)
possessing muscular strength	possessing muscular strength
an imaginative lively style (especially style of writing)	a cord or band of inelastic tissue connecting a muscle with its bony attachment
the physiological state of having or consisting of muscle