noun

• (figuratively) Something that stimulates, encourages or maintains an action.
  "His books were fuel for the revolution."

verb

• (transitive) To provide with fuel.
  "[…] Lieutenant Hirsch appeared with a sheaf of signals in his hand. He took these from the young man and read them through. Mostly they dealt with routine matters of the fuelling and victualling, but one from the Third Naval Member’s office was unexpected."
• (transitive) To exacerbate, to cause to grow or become greater.
  "There were times, during the first two years of the Biden presidency, when I came close to forgetting about it all: the taunts and the provocations; the incitements and the resentments; the disorchestrated reasoning; the verbal incontinence; the press conferences fueled by megalomania, vengeance, and a soupçon of hydroxychloroquine."