preadmission

[ pree-ad-mish-uhn ]

noun

1. (in a reciprocating engine) admission of steam or the like to the head of the cylinder near the end of the stroke, as to cushion the force of the stroke or to allow full pressure at the beginning of the return stroke.

Word History and Origins

Origin of preadmission¹

First recorded in 1885–90; pre- + admission