speedfreak

/S P IY1 D F R IY1 K/
noun
  1. 1

    (slang) An addict or habitual user of amphetamines, methamphetamines, or similar stimulating drugs.

  2. 2

    (slang) A person who enjoys driving, riding motorcycles, etc. at high speeds.

  3. 3

    (slang) A metalhead who listens to speed metal.