/ Dictionary / Index P prime interest rate: Meaning and Definition of Find definitions for: prime' in'terest rate" Pronunciation: [key] — Banking. Banking. SeeAlso called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. prime ideal primely Related Content Daily Word Quiz: eureka Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language