n. 1 (often in pl.) a set of toothe wheels that work together, esp. those connecting the engine of a vehicle to th road wheels. b particular setting o these (first gear). 2 equipment, appar atus, or tackle. 3 colloq. clothing. v. (foil. by to) adjust or adapt to. 2 (ofte foil. by up) equip with gears. 3 (foil. b up) make ready or prepared. 4 put i gear. o in gear with a gear engaged. out :1 of gear with no gear engaged. [Old Norse]