/ Dictionary / Index P prime minister: Meaning and Definition of Find definitions for: prime" min'ister Pronunciation: (prīm'min"u-stēr'ē-ul), [key] the principal minister and head of government in parliamentary systems; chief of the cabinet or ministry: the British prime minister. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. prime meridian prime mover Related Content Daily Word Quiz: exemplary Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language