atomic mass unit

/AH0 T AA1 M IH0 K M AE1 S Y UW1 N AH0 T/
noun
  1. 1

    A unit of mass equal to 1/12 the mass of an atom of the 12C isotope of carbon.

Synonyms

Source: https://en.wiktionary.org/wiki/atomic%20mass%20unit