TWITCH

I. verb Etymology: Middle English twicchen; akin to Old English twiccian to pluck, Old High German gizwickan to pinch Date: 14th century transitive verb to move or pull with a sudden motion ; jerk , intransitive verb pull , pluck , to move jerkily ; quiver , to undergo a brief spasmodic muscular contraction , ~er noun II. noun Date: 1523 an act of ~ing, a physical or mental pang , a loop of rope or strap that is tightened over a horse's lip as a restraining device, 4. a brief spasmodic contraction of the muscle fibers, a slight jerk of a body part, ~ily adverb ~y adjective III. noun Etymology: alteration of quitch Date: 1595 quack grass