WordNet sense 1 (used of old persons or old trees; covered with knobs or knots):

gnarled, knotty, gnarly, knobbed

WordNet sense 2 (having or marked by bends or angles; not straight or aligned):

crooked, crooked

WordNet sense 3 (tangled in knots or snarls):

snarly, snarled

WordNet sense 4 (in a confused mass):

tangled

WordNet sense 5 (fastened with strings or cords):

fastened, tied