cycloaddition

[ sahy-kloh-uh-dish-uh n, sik-loh- ]
/ ˌsaɪ kloʊ əˈdɪʃ ən, ˌsɪk loʊ- /

noun Chemistry.

the formation of a cyclic compound by the addition reaction of unsaturated molecules.

Origin of cycloaddition

First recorded in 1960–65; cyclo- + addition