noun
: any of various reversing or speed-changing gears used especially in modern machine tools that have one or more idle wheels journaled in a swinging frame moved and clamped in position by the operator
noun
: any of various reversing or speed-changing gears used especially in modern machine tools that have one or more idle wheels journaled in a swinging frame moved and clamped in position by the operator
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012