/ Dictionary / Index P psia: Meaning and Definition of Find definitions for: psia Pronunciation: [key] pounds per square inch, absolute. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. psi psid Related Content Daily Word Quiz: fervor Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language