6 letters · 12 points in Scrabble
adjective (of meat) full of sinews; especially impossible to chew
adjective consisting of tendons or resembling a tendon
adjective (of a person) possessing physical strength and weight; rugged and powerful
originInherited from Middle English synwy, synewy, synowy (“tendonous”); equivalent to sinew + -y.
Etymology from Wiktionary, CC BY-SA 3.0