/ Dictionary / Index P PSA: Meaning and Definition of Find definitions for: PSA Pronunciation: [key] prostate specific antigen: a blood test to detect prostate cancer. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: psa (Thesaurus) PS psalm Related Content Daily Word Quiz: rustic Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language