operon
noun
op·er·on ˈä-pə-ˌrän 
: a group of closely linked genes that produces a single messenger RNA molecule in transcription and that consists of structural genes and regulating elements (such as an operator and promoter)
Word History
Etymology
borrowed from French opéron, from opérer "to bring about, effect" (going back to Middle French, borrowed from Late Latin operārī "to work, be efficacious") + -on -on entry 2 — more at operate
First Known Use
1960, in the meaning defined above
Medical Definition
operon
noun
op·er·on ˈäp-ə-ˌrän
: a group of closely linked genes that produces a single messenger RNA molecule in transcription and that consists of structural genes and regulating elements (as an operator and promoter)