noun
mass defect
Physics term: the difference between the mass of an atomic nucleus and the sum of the masses of its individual nucleons.
原子核の質量欠損は、核子の結合エネルギーに相当する。
The mass defect of an atomic nucleus corresponds to the binding energy of the nucleons.
Compound of 質量 (mass) and 欠損 (deficit, loss). The term is a direct translation of the English 'mass defect'.