Etymological Note: Originally jocular or colloquial Scots for ‘turnip.’ Common insult tumshie-head and other comparisons of a head to a turnip probably preceded the stand-alone tumshie.
Citations:
[1947Dictionary of the Scots Language: A jocular or colloq. name for a turnip.] 1993 Mary Lockhart The Herald (Glasgow, Scotland) (Mar. 23) “Eggs and the oaf” p. 16: We are given a blustering blundering tumshie, jingling keys and flapping his arms against his sides like a penguin on ecstasy. 1996 Charles Duncan Scottish Daily Record (Scotland) (May 22) “The Voice Of Scotland” p. 14: While doing my weekly shopping in our local supermarket, I was choosing a turnip and was appalled at the price of one—70-90p depending on size and they were tiny!…You’d be a right “tumshie” to pay that much for a neep! 1996 M. C. Beaton (June 1) “Death of a Macho Man” 1997 reiussue ed., p. 3: Now we all hae tae listen tae that big tumshie, blethering on and on and on. 1996 [imcc@cs.strath.ac.uk (Iain McCord)] Usenet: rec.arts.drwho (Dec. 2) “Re: Kill files”: Whit ur ye bluhtherung aboot ya tumshie. 1999 [patent3@popmail.dircon.co.uk (Stewart Pinkerton)] Usenet: rec.audio.opinion (Dec. 26) “Re: The great LP vs CD debate/war”: Och, ye muckle tumshie, hae ye nae sense avah? 1999 [david@wedding-services.demon.co.uk] Usenet: soc.culture.scottish (Dec. 29) “Re: Bye For Now, You Losers”: Well good riddance you auld tumshie. 2000 [Connor Macleod] Usenet: uk.rec.climbing (July 19) “Re: wh&s;run amok”: No an insult would be if I called you a “richt sasenach Tumshie, wi a heid the’ size o’ ben macduhi.” Then you would have every right to be offended. 2004 Simon Pia Scotsman (Scotland) (Nov. 3) “Yes, folks, tumshie is the new numpty”: Forget about these two tumshies, Bush and Kerry.…Indeed, the Diary even prefers the term “tumshie” to “numpty."…We are assured, a great afternoon for anyone feeling depressed—if Bush wins—at a tumshie as leader of the free world.