Green’s Dictionary of Slang

pinhead adj.

also pinheaded
[pinhead n. (2)]

stupid, with a small brain.

[US]Morn. Appeal (Carson City, NV) 25 Dec. 3/4: It will seem rather hard if so bright [...] a man as Von Read is beaten [...] by a lot of pinheaded, jacklegged little gallinippers.
Bismarck Wkly Tibune (ND) 24 Mar. 7/4: The pinheaded editor who wrote that is utterly incapable of understanding.
[US]Ade Forty Modern Fables 67: Is it not Sad to see a pin-headed Rake dissipating a Large Fortune?
[US]‘O. Henry’ ‘The Clarion Call’ in Voice of the City (1915) 194: They send a lot of pin-head reporters around to the scene.
[UK]Sporting Times 27 Aug. 1/2: That sort o’ bluff may go with some o’ the pin-head conks, but we know better.
[US]J. Lait ‘Annye’s Ma’ in Beef, Iron and Wine (1917) 281: He asks you what you can expect from such a soused manager and such a pinhead press agent.
[US]‘Commander’ Clear the Decks! 77: Take your eyes off me, you pin-headed plebe, and thin out!
[US]R. McAlmon ‘Summer’ in A Hasty Bunch 234: They were whining sorts, and both pinheaded old people.
[US]J. Lait Gangster Girl 85: I’m just a pinheaded dame, chasin’ pleasure.
[US]J. Weidman Price Is Right 188: Doesn’t that pinheaded idiot understand a simple thing like --?
[UK]C. MacInnes Mr Love and Justice (1964) 68: Others invested in huge wardrobes or fast cars: but this, except among the pin-headed, was considered most unwise.
[Aus]H. Porter Paper Chase 247: The man with the walking-stick listening to the waves nudging pin-headedly at the threadbare sands.
[Aus]M. Harris Angry Eye 230: The students shamble out of the open classroom at school to the open situation of the university, intellectually pinheaded.
[US]C. Hiaasen Double Whammy (1990) 210: Maybe the pinhead hydrologist could work a few miracles.
[Can]M. Atwood Cat’s Eye (1989) 218: He doesn’t want me to be a pin-headed fuzzbrain.
[US](con. c.1970) G. Hasford Phantom Blooper 78: You pinheaded no-brained foreskin-chewing pogey bait maggots, you are lower than worm life!
[Aus]S. Maloney Something Fishy (2006) 225: And where were the pinhead pigs?