To be taken for a mug

Hello,.. I appreciate your telling me the meaning and the origin of the above phrase. Thank you.

I think it means to be treated or thought of as stupid.

Brewer's Dictionary of Phrase and Fable suggests that it might come from the Romany for 'fool' or 'simpleton'.

DFG

Stupid--or gullible (perhaps a subcategory of stupid). Mug, in OED: "1. A stupid or incompetent person; a fool or simpleton; a gullible person, a dupe. . . . mug's game, a thankless task; a useless, foolish, or unprofitable activity." To be taken for a mug most often means to be regarded as excessively gullible. Or so it seems to me. SS