What's the derivation of the meaning of the word "double-dome," meaning intellectual?
It seem that it is just the image of a 'dome' similar to a bald head at the origin of the saying:
- (slang) (mildly derogatory) Alternative spelling of doubledome An intellectual or scholar. (Wiktionary)
- The word conjures the image of two bald-headed men putting their heads together in an effort to solve a problem.
According to The Oxford Dictionary of American Political Slang and the The Routledge Dictionary of Modern American Slang and Unconventional English the term was in use in the 40's in the US.
- 1943 H.A. Smith Putty Knife Factory 207: Arthur Birsbane [ 1936]...was known among fellow newspapermen as Old Double Dome.
The term is a synonym of egghead where the reference to a bald head is similar.
1907, "bald person," from egg (n.) + head (n.). Sense of "intellectual" is attested from 1918
presumably fr the putative high, domed, egg-shaped heads of such persons; the term was used in a letter of Carl Sandburg about 1918]
Cupola (dome) del Brunelleshi - Florence