Meaning

noun a cord or band of inelastic tissue connecting a muscle with its bony attachment

noun possessing muscular strength

originFrom Middle English synwe, synewe (“tendon; ligament or other connective tissue; muscle; nerve; leaf vein”), from Old English sinu (“tendon, sinew; nerve”), from Proto-West Germanic *sinu, from Proto-Germanic *sinwō, *senawō (“sinew”), from Proto-Indo-European *snéh₁wr̥ (“sinew, tendon”), from *(s)neh₁- (“to twist (threads), spin, weave”). The word is cognate with sinnow (“sinew”), Scots senon,…

Etymology from Wiktionary, CC BY-SA 3.0