instroke

[ in-strohk ]
/ ˈɪnˌstroʊk /

noun

a stroke traveling in an inward direction.
(in an engine) the stroke during which the piston moves into the cylinder.

Origin of instroke

First recorded in 1885–90; in + stroke1
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019