noun

a toothed wheel that works with others to alter the relation between the speed of a driving mechanism (such as the engine of a vehicle) and the speed of the driven parts (the wheels).

a racing bike with ten-speed gears

gearwheel,toothed wheel,cog,cogwheel,gear ratio,speed

verb

prepare, adjust, or equip for a particular purpose or need.

they gear workouts to your specific needs