Green’s Dictionary of Slang

dur-brain n.

also duh-brain
[echoic of the stupid person’s grunt duh! excl. or dur]

(UK juv.) a fool.

Show quotations
[UK]P. Theroux Kowloon Tong 182: But I’m a dur-brain. Would you mind repeating the conditions?
[UK]Guardian Guide 26 Feb.–3 Mar. 7: The postmodernism for dur-brains.
OnLine Dict. of Playground Sl. 🌐 duh-brain n. somebody particularly stupid in a joey type style.
[UK]D. Mitchell Black Swan Green 346: The BBC only spot secret meanings [i.e. in songs] after the dimmest duh-brain in Duffershire’s got it.