/ Dictionary / Index F Fermat's theorem: Meaning and Definition of Find definitions for: Fermat's' the'orem Pronunciation: [key] — Math. Math. the theorem that an integer raised to a prime power leaves the same remainder as the integer itself when divided by the prime. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Fermat's principle ferment Related Content Daily Word Quiz: gregarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language