/ Dictionary / Index D differential operator: Meaning and Definition of Find definitions for: dif'feren'tial op'erator Pronunciation: [key] — Math. Math. a function, usually expressed as a polynomial, that indicates linear combinations of the derivatives of the expression on which it operates. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. differential geometry differential psychology 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