v. & n.
v. 1 intr. (of the features, muscles, limbs, etc.) move or contract spasmodically. 2 tr. give a short sharp pull at.
n. 1 a sudden involuntary contraction or movement. 2 a sudden pull or jerk. 3 colloq. a state of nervousness. 4 a noose and stick for controlling a horse during a veterinary operation. twitchy adj. (twitchier, twitchiest) (in sense 3 of n.).
[ ME f. Gmc: cf. OE twiccian, dial. twick ]