noun
: a control on the left-hand platen knob of a typewriter that disengages the line space lever to allow writing at positions other than those normally turned up by the ratchet
noun
: a control on the left-hand platen knob of a typewriter that disengages the line space lever to allow writing at positions other than those normally turned up by the ratchet
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012