- any material, as coal, oil, gas, wood, etc., burned to supply heat or power
- fissile material from which nuclear energy can be obtained, as in a nuclear reactor
- anything that maintains or intensifies strong feeling, etc.
ME fewell < OFr fouaille < ML fuale, focale < foca, hearth, for L focus, fireplace: see focus
transitive verb fueled or fuelled, fueling or fuelling
to supply with fuel