sinewy
sinew + -y
https://gyazo.com/ba6c3a398a2febb2b984e64574397e14
adjective
consisting of or resembling sinews.
腱質の, 筋ばった; 筋の多い
(of a person or animal) lean and muscular:
筋骨たくましい
e.g. a short, sinewy, sunburnt man
e.g. figurative : the language is spare and sinewy.