taut
adjective
1 the rope went taut:
tight, tightly stretched, stretched, rigid, stressed, not slack, not loose.
▷antonyms slack, loose.
2 his muscles remained hard and taut:
flexed, tensed, tightened, hard, solid, firm, rigid, stiff, unyielding.
▷antonyms relaxed.
3 he glared at her with a taut expression:
fraught, strained, stressed, tense, drawn, drained, sapped, fatigued, tired;
informal uptight.