(rail transport) On a steam locomotive, a powered wheel driven by the locomotive's pistons or turbine.

(rail transport) On a steam locomotive, an unpowered wheel or axle located behind the driving wheels.

a revolving crib set in the wall of a church or convent, allowing an abandoned baby to be left anonymously and safely.

The combination button/scroll wheel selection device of some iPods.

plural of click wheel

A small, rotating circular table of variable speed used in the manufacture of ceramics.

(mythology, philosophy) The wheel of Fortune.

(idiomatic) A person with a great deal of power or influence, especially a high-ranking person in an organization. / (UK, Ireland) A Ferris wheel. / (US) A low-riding tricycle with a large front wheel.

Having four wheels / Having a transmission that drives all four wheels.

(figuratively) Anything designed to make something easier for a novice.