The Collaborative International Dictionary of English v.0.48:

norepinephrine \norepinephrine\ n.
   A hormone (C8H11NO3) secreted by the adrenal medulla; it
   also serves as a neurotransmitter, released at synapses;
   called also noradrenaline. Chemically it is
   2-amino-1-(3,4-dihydroxyphenyl)ethanol. It is a precursor of
   epinephrine in the body.

   Syn: noradrenaline.
        [WordNet 1.5] norethandrolone