v. & n.
v. 1 tr. (often foll. by up) twist; entangle; confuse and hamper the movement of (traffic etc.). 2 intr. (often foll. by up) become entangled, congested, or confused. 3 tr. adorn the exterior of (a narrow metal vessel) with raised work.
n. a knot or tangle. snarling iron an implement used for snarling metal. snarl-up colloq. a traffic jam; a muddle; a mistake.
[ ME f. snare (n. & v.): sense 3 perh. f. noun in dial. sense 'knot in wood' ]