Green’s Dictionary of Slang

egghead n.1

(orig. US)

1. an intellectual, anyone considered to work with brain rather than brawn.

[US]O. Johnson Sat. Eve. Post 16 Nov. 9/1: His genius lived in the nicknames of the Egghead [...] and the Coffee Cooler.
[US]S.F. Call 21 May 6/1: The Triumphant Egghead had discovered the resemblance.
[UK] C. Sandburg Letter (deposited in Toledo-Lucas County Public Library, Toledo, OH) n.p.: Dear N. D.‘[...] Egg heads’ is the slang here for editorial writers.
[US]R. Chandler Long Good-Bye 289: I told him I didn’t think it would do Springer any harm. ‘Only with the eggheads,’ Lonnie Morgan said, ‘and they already had his number.’.
[US]E. De Roo Young Wolves 20: If those eggheads give you any trouble let me know.
[US]S. Longstreet Flesh Peddlers (1964) 158: Mon, yo’ is a egghead.
[US]‘Iceberg Slim’ Pimp 138: She sounds like an egghead.
[US]Fantastic Four Annual 16: Even a non-egghead like me can figure out what’s happening.
[UK]T. Blacker Fixx 216: Some group of professional busybodying eggheads.
[US]P. Beatty White Boy Shuffle 157: The ersatz egghead lived in Cheviot Heights.
[UK]Guardian Weekend 5 June 34: She [...] sent him to a Farm Street egghead for the final brush-up.
[US]W.T. Vollmann Royal Family 5490: I’d rather not quote Gibbon. The guy was an egghead.
[US]K. Huff A Steady Rain I i: You are the egghead. I am the walrus.

2. a pretentiously intellectual type.

[US]I. Reed Free-Lance Pallbearers 129: You gotta watch these eggheads.
[UK]H.E. Bates A Little of What You Fancy (1985) 452: On one occasion [...] she had thrown over the fence, like a verbal hand grenade, the phrase ‘red egghead!’.