thousandth mass unit

thousandth mass unit

[′thau̇z·ənth ′mas ′yü·nət]
(physics)
A unit of energy equal to the energy equivalent of a mass of 10-3 atomic mass unit according to the Einstein mass-energy relation, that is, to the product of 10-3 atomic mass unit and the square of the speed of light; equal to approximately 1.49176 × 10-13 joule.