'anti-charlatan' originates from the prefix 'anti-' (from Greek 'anti-' meaning 'against') combined with 'charlatan' (from Italian/French), specifically the Italian 'ciarlatano' or French 'charlatan'.

'charlatan' entered English from Italian 'ciarlatano' (also influenced by French 'charlatan'), originally from 'ciarlare' meaning 'to chatter'; the prefix 'anti-' comes from Greek 'anti-' meaning 'against'. The compound 'anti-charlatan' is a modern English formation combining these elements to mean 'against charlatans'.

Initially, the components meant 'against' and 'a chatterer/trickster' respectively; over time the compound has come to mean broadly 'opposed to fraudulent practitioners' rather than a literal opposition to chatter.