dopamine UK /ˈdəʊ.pə.miːn/US /ˈdoʊ.pəˌmin/ noun1 •A monoamine C₈H₁₁NO₂ that is a decarboxylated form of dopa, present in the body as a neurotransmitter and a precursor of other substances including adrenalin.Epinephrine and dopamine are two other catecholamine transmitters. — 1988 formsdopamines