adjective. (of drugs e.g.) able to excite or stimulate.
1. Noun, singular or mass Specifically, U.S. and Brazilian scientists reported that hydrogen peroxide may slow your heart by tampering with the transmission of an important excitatory amino acid called L-glutamate. 2. Adjective Acetylcholine is an excitatory neurotransmitter, meaning that it stimulates the brain, as contrasted with an inhibitory neurotransmitter that has a calming effect.