twitch

A brief, small (sometimes involuntary) movement out of place and then back again; a spasm.

A brief, contractile response of a skeletal muscle elicited by a single maximal volley of impulses in the neurons supplying it.

A trip taken in order to observe a rare bird.

(informal) Action of spotting or seeking out a bird, especially a rare one.

couch grass (Elymus repens; a species of grass, often considered as a weed)

A stick with a hole in one end through which passes a loop, which can be drawn tightly over the upper lip or an ear of a horse and twisted to keep the animal quiet during minor surgery.

The sudden narrowing almost to nothing of a vein of ore.

To perform a twitch; spasm.

To cause to twitch; spasm.

To jerk sharply and briefly.

To spot or seek out a bird, especially a rare one.

To engage in twitching.

(no longer used) To exert oneself.