superhard

/S UW1 P ER0 HH AA1 ER0 D/
adjective
  1. 1

    Having a very high hardness.

  2. 2

    Highly strengthened against attack.

  3. 3

    (not comparable, mineralogy) Having a hardness between that of boron nitride and that of diamond.

noun
  1. 1

    (motor racing) A tyre whose compound is harder than a normal hard tyre.