noun. A receptive being that joins and reacts to norepinephrine and epinephrine too, though not as much. It behaves as a neurotransmitter in the SNS. Both alpha and beta receptors exist. Commonly referred to as adrenergic receptors and andrenoceptors.
ADRENORECEPTOR: "Alpha- and beta-andrenoreceptors are the two kinds of adrenergic receptors which operate in such a way as to permit the carrying out of adrenaline-like messages throughout the SNS."