Wordnet 3.0
NOUN (2)
1. a unit of pressure;
[syn: pounds per square inch, psi]
2. the 23rd letter of the Greek alphabet;
V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006):
PSI Performance Systems International, inc.V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006):
PSI Published Subject Indicator (XTM)

