/ Dictionary / Index F fuel oil: Meaning and Definition of Find definitions for: fu'el oil" Pronunciation: [key] an oil used for fuel, esp. one used as a substitute for coal, as crude petroleum. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. fuel injector fuel rod 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