(1) Relating to acetylcholine, e.g. cholinergic neuron.
(3) Activated by or capable of releasing acetylcholine.
A cholinergic agent may act directly, e.g. by stimulating the acetylcholine receptors (the same way that the acetylcholine does), or indirectly by inhibiting cholinesterase, promoting the release of acetylcholine.
Related forms: cholinergically (adverb).