
• (n.) admission, as of steam, to the engine cylinder before the back stroke is completed, thus increasing the cushioning. • (n.) Lit., previous admission;
Found on
http://thinkexist.com/dictionary/meaning/preadmission/
Pre`ad·mis'sion noun Lit., previous admission; specif.
(Engineering) , admission, as of steam, to the engine cylinder before the back stroke is completed, thus increasing the cushioning.
Found on
http://www.encyclo.co.uk/webster/P/143

(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.
Found on
https://www.infoplease.com/dictionary/preadmission
No exact match found.