Definitions of fuel:

• noun:   a substance that can be consumed to produce energy

  Example: "More fuel is needed during the winter months"

• verb:   take in fuel, as of a ship

  Example: "The tanker fueled in Bahrain"

• verb:   provide with a combustible substance that provides emergy

  Example: "Fuel aircraft, ships, and cars"

• verb:   provide with fuel
• verb:   stimulate

  Example: "Fuel the debate on creationism"

• name:  A surname (very rare: popularity rank in the U.S.: #40718)