/ Dictionary / Index I incidental: Meaning and Definition of Find definitions for: in•ci•den•tal Pronunciation: (in"si-den'tl), [key] — adj. happening or likely to happen in an unplanned or subordinate conjunction with something else. incurred casually and in addition to the regular or main amount: incidental expenses. likely to happen or naturally appertaining (usually fol. by to). —n. something incidental, as a circumstance. minor expenses. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: incidental (Thesaurus) incident incidentally Related Content Daily Word Quiz: cetacean Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language