[{"Bold_text": "noun", "List Items": ["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.", "Also called oil derrick oil derrick.the towerlike framework over an oil well or the like.", "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."]}, {"Bold_text": "verb (used with or without object)", "List Items": ["Machinery. luff ."]}]