/ Dictionary / Index C cu. in.: Meaning and Definition of Find definitions for: cu. in. Pronunciation: [key] cubic inch; cubic inches. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. cui bono* cuirass Related Content Daily Word Quiz: alacrity Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language