Crossword solverSynonyms for fossil fuel9 crossword answers for “fossil fuel” (6,4), sorted by letter count.How many letters?All93142517181921013 letters 1gas4 letters 2fuelcoal5 letters 1crude7 letters 1rock oil(4,3)8 letters 1crude oil(5,3)9 letters 2fossil oil(6,3)petroleum10 letters 1natural gas(7,3)