define acetylcholine
Medical Definition of ACETYLCHOLINE. : a neurotransmitter C7H17NO3 released at autonomic synapses and neuromuscular junctions, active in the transmission of nerve impulses, and formed enzymatically in the tissues from choline.â aceÂ·tylÂ·choÂ·linÂ·ic \-kÅ-Ëlin-ik\ adjective.efinition of ACETYLCHOLINE. : a neurotransmitter [C7H16NO2]+ released at autonomic synapses and neuromuscular junctions and formed enzymatically in the tissues from choline. See acetylcholine defined for kids. ADVERTISEMENT.