Meaning of STROKE in English
( v. t. )
The movement, in either direction, of the piston plunger, piston rod, crosshead, etc., as of a steam engine or a pump, in which these parts have a reciprocating motion; as, the forward stroke of a piston; also, the entire distance passed through, as by a piston, in such a movement; as, the piston is at half stroke.
Webster's Revised Unabridged English Dictionary. Пересмотренный полный словарь английского языка Webster. 2012