/ Dictionary / Index D diesel fuel: Meaning and Definition of Find definitions for: die'sel fu"el Pronunciation: [key] a combustible petroleum distillate used as fuel for diesel engines. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. diesel engine dieseling Related Content Daily Word Quiz: feline Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language