| 1. | Machinery. a jib crane having a boom hinged near the base of the mast so as to rotate about the mast, for moving a load toward or away from the mast by raising or lowering the boom. |
| 2. | Also called oil derrick. the towerlike framework over an oil well or the like. |
| 3. | a boom for lifting cargo, pivoted at its inner end to a ship's mast or kingpost, and raised and supported at its outer end by topping lifts. |
| 4. | Machinery. luff. |
