| Noun | 1. | nuclear fusion reaction - a nuclear reaction in which nuclei combine to form more massive nuclei with the simultaneous release of energy cold fusion - nuclear fusion at or near room temperatures; claims to have discovered it are generally considered to have been mistaken nuclear reaction - (physics) a process that alters the energy or structure or composition of atomic nuclei thermonuclear reaction - a nuclear fusion reaction taking place at very high temperatures (as in the sun) |