Crossword clues for the word: FOSSILFUEL The word FOSSILFUEL has appeared as an answer to at least 6 crossword clues on different crossword puzzles. Crossword clues for FOSSILFUEL Showing 1 to 6 of 6 results Clue(s) "End of a quip from the ""Shoe"" comic" "Oil, coal, etc." Coal or natural gas Conventional energy source Natural gas, coal, etc. Natural gas, e.g.