Used both as the comparative form of the adjective "idle" and, attributively, before another noun to denote a mechanical part that supports or transmits motion without driving.
Translations
fouTechnique, en parlant d’un engrenage, d’une roue ou d’une poulie qui tourne librement sans entraîner.
The idler gear meshes with the primary gears to reverse the direction of rotation.
Le pignon fou s’engrène avec les engrenages principaux pour inverser le sens de rotation.
Definitions
Attributive. Relating to or functioning as an idler gear, pulley, wheel, etc., that guides or transmits motion without driving.
The idler gear meshes with the primary gears to reverse the direction of rotation.