1. preadmission - Noun
2. preadmission - Adjective
preadmission (not comparable)
Before admission (to a hospital, university, etc.).
A preadmission process; a process that precedes admission.
(by extension, health care) A preliminary process that precedes hospital admission for some interventional or surgical procedures.
Admission, as of steam, to an engine cylinder before the backstroke is completed, thus increasing the cushioning.
Source: en.wiktionary.org