Main Entry: nor·epi·neph·rine

Pronunciation: \ˌnȯr-ˌep-ə-ˈnef-rən, -rēn\

Function: noun

: a catecholamine C₈H₁₁NO₃ that is the chemical means of transmission across synapses in postganglionic neurons of the sympathetic nervous system and in some parts of the central nervous system, is a vasopressor hormone of the adrenal medulla, and is a precursor of epinephrine in its major biosynthetic pathway—called also arterenol, noradrenaline; see levophed