/ Dictionary / Index F fossil fuel: Meaning and Definition of Find definitions for: fos'sil fu"el Pronunciation: [key] — Energy. Energy. any combustible organic material, as oil, coal, or natural gas, derived from the remains of former life. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. fossil fossil gum 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