buckle

nouns

fastener that fastens together two ends of a belt or strap; often has loose prong
buckle
is a type of (narrower)
restraint that attaches to something or holds something in place
fastener, fastening, fixing, holdfast
a shape distorted by twisting or folding
buckle, warp

verbs

fasten with a buckle or buckles
buckle, clasp
antonym
unbuckle
fold or collapse
"His knees buckled"
buckle, crumple
bend out of shape, as under pressure or from heat
"The highway buckled during the heat wave"
buckle, heave, warp