nuclear reaction nuc·lear·reac·tion uncommon noun 1. (physics) a process that alters the energy or structure or composition of atomic nuclei Synonymsnuclear reaction Related words Broader terms natural process Narrower terms chain reactiondecayendoergic reactionexoergic reactionfissionfusionspallation WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.
