the.com/nuclear fusion

means Nuclear fusion is a process where two light atomic nuclei, usually hydrogen, are forced together under extreme heat and pressure to form a heavier nucleus, releasing a burst of energy in the process.

from 'Nuclear' traces back to Latin nucleus, meaning 'kernel' or 'little nut' — the hard center of a thing, borrowed by physicists in the early 20th century to name the dense core of the atom. 'Fusion' comes from Latin fundere, 'to pour' or 'melt together,' the same root that gives us 'fuse' and 'foundry.' The term 'nuclear fusion' itself emerged in the 1930s, once physicists like Eddington and later Bethe worked out that stars generate their heat not by burning fuel in the ordinary sense, but by melting atomic nuclei into new, heavier ones.