'antimuscarinic' is formed from the prefix 'anti-' (from Greek anti- meaning 'against') combined with 'muscarinic', which derives from 'muscarine' (an alkaloid named after the fly agaric fungus); 'muscarine' ultimately traces to Latin 'muscarius' meaning 'of flies' (from 'musca' = 'fly').

'muscarine' (name given to the alkaloid isolated from Amanita muscaria) gave rise to the adjective 'muscarinic' (relating to the effects of muscarine), and in the 20th century the compound form 'antimuscarinic' developed to denote substances opposing muscarinic action.

Initially the element referred specifically to opposing the effects of the compound 'muscarine'; over time it broadened to mean 'blocking muscarinic acetylcholine receptors' in general pharmacological usage.