jig

Concise Oxford English Dictionary © 2008 Oxford University Press:
jig/ʤɪɡ/

▶noun

• 1 a lively dance with leaping movements.

  ■ a piece of music for a jig, typically in compound time.

• 2 a device that holds a piece of work and guides the tool operating on it.

• 3 Fishing a type of artificial bait that is jerked up and down through the water.

▶verb (jigs, jigging, jigged)

• 1 dance a jig.

• 2 move up and down jerkily.

• 3 equip (a workshop) with a jig or jigs.

• 4 fish with a jig.

– phrases
in jig time N. Amer. informal extremely quickly.
the jig is up N. Amer. informal the game is up.

– origin C16: of unknown origin.