a type of crane (= machine with a part like a long arm) used for moving heavy things esp. on ships, or a tall structure above a well (= hole in the ground) from which oil is taken

TRANSPORT a type of crane (= tall machine for moving heavy things) with a long part like an arm, used especially for moving things on and off ships

NATURAL RESOURCES, PRODUCTION a tower above an oil well which supports the drill (= machine for making a hole in the ground)