Swivel /(?)/

Swiv·el

Swivel

n.
  1. A piece, as a ring or hook, attached to another piece by a pin, in such a manner as to permit rotation about the pin as an axis. (Mech.)
  2. A small piece of ordnance, turning on a point or swivel; -- called also swivel gun. (Mil.)

Phrases & Compounds
Swivel bridge
a kind of drawbridge that turns round on a vertical axis; a swing bridge.
Swivel hook
a hook connected with the iron strap of a pulley block by a swivel joint, for readily taking the turns out of a tackle.
Swivel joint
a joint, the two pieces composing which turn round, with respect to each other, on a longitudinal pin or axis, as in a chain, to prevent twisting.

Swivel

v. i.
  1. To swing or turn, as on a pin or pivot.