/ Dictionary / Index S square inch: Meaning and Definition of Find definitions for: square' inch' Pronunciation: [key] a unit of area measurement equal to a square measuring one inch on each side; 6.452 square centimeters. Abbr.: in, sq. in. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. squarehead square kilometer Related Content Daily Word Quiz: procrastinate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language