'cholinergic' originates from the combination of 'choline' and the suffix '-ergic', where 'choline' refers to a nutrient that is a precursor to acetylcholine, and '-ergic' means 'activated by'.

'choline' was derived from the Greek word 'khole', meaning 'bile', and '-ergic' was adapted from the Greek 'ergon', meaning 'work'.

Initially, it referred to any substance that mimicked the action of acetylcholine, but now it broadly refers to anything related to acetylcholine activity.