Wordnet 3.0
NOUN (1)
1. 
 a protein manufactured exclusively by the prostate gland; 
 PSA is produced for the ejaculate where it liquifies the semen and allows sperm cells to swim freely; 
 elevated levels of PSA in blood serum are associated with benign prostatic hyperplasia and prostate cancer; 
[syn: prostate specific antigen, PSA]
WordNet (r) 3.0 (2006):
prostate specific antigen
    n 1: a protein manufactured exclusively by the prostate gland;
         PSA is produced for the ejaculate where it liquifies the
         semen and allows sperm cells to swim freely; elevated
         levels of PSA in blood serum are associated with benign
         prostatic hyperplasia and prostate cancer [syn: prostate
         specific antigen, PSA]