Green’s Dictionary of Slang

(orig. Irish) a painfully stupid or gullible person, a fool.

1837		‘Terence O’Shaughnessy’ in Bentley’s Misc. Jan. 42: That the O’Finns and O’Shaughnessys should be disgraced by a mean-spirited gommouge of your kind.
1893		F.P. Dunne in Schaaf Mr Dooley’s Chicago (1977) 271: Listen to me, Jawn, ye poor deluded gom.
1904		G.B. Shaw John Bull’s Other Island II ii: Yah, you great gaum, you!
1908		J. Guinan Soggarth Aroon 78: Musha, Tom Malley, but aren’t you the soft gom of a gossoon to be beat up so easily.
1910		P.W. Joyce Eng. As We Speak It In Ireland (1979) 261: Gawm, gawmoge; a soft foolish fellow.
1918		K.F. Purdon Dinny on the Doorstep 166: But Dinny! the innocent little gaum.
1940		‘Flann O’Brien’ Third Policeman (1974) 164: You are very intellectual and I am certain I am nothing but a gawm.
1941		Britannia & Eve (London) 1 May 73/1: He gave Natty one real up-driven smasher on his flesh proboscis. ‘That poor gom!’.
1942		(con. 1890s) S. O’Casey Pictures in the Hallway 122: I’m no gaum.
1948		K. Williams Diaries 26 Jan. 20: Of course he just isn’t true, and not a little unlike a gorm.
1953		L. Doyle Back to Ballygullion 156: An’ when that poor gawm made a rush for her.
1959		I. & P. Opie Lore and Lang. of Schoolchildren (1977) 201: He is – a clodpoll [...] a brainless gorm.
1961		(con. 1890–1910) ‘Flann O’Brien’ Hard Life (1962) 106: We’d look like bloody gawms.
1966		Eve. Press 21 Nov. n.p.: Goms are not famous for their mental brilliance [...] it’s not unusual to hear questions ‘What kind of gom is he?’ or ‘Did you ever see a gom like that before?’ [BS].
1966		P. Boyle At Night All Cats Are Grey 196: You’ll have little enough to laugh about if you have poled Cassie as you poled that poor silly ghomey from the Crooked Bridge.
1969		P. Boyle All Looks Yellow to the Jaundiced Eye 66: She’ll be sorely missed. Four weans and a thaveless gawm of a father.
1971		T. Murphy Morning After Optimism in Plays: 3 (1994) Scene iv: Who’s the gomey?
1973		H. Leonard Da (1981) Act I: They said I’d rue the day, and the gawm I was, I didn’t believe them.
1985		T. Murphy Conversations on a Homecoming (1986) 39: He was a gomey if you ask me.
1995		P. O’Keeffe Down Cobbled Streets, A Liberties Childhood 135: ‘Don’t be a gom,’ Betty snapped.
2001		G. Coughlan Everyday Eng. and Sl. 🌐 Gom, Gombeen (n): idiot.
2007		D. Keenan Complete Encyc. of Gaelic Football 23: He must be a complete gom, with no sense at all. That's what has this country the way it is.
2017		Irish Indep. 18 Nov. 🌐 The faces of civil servants [...] signalled that the foreign secretary had blown the exam. In fact, it was abundantly clear both sets politely considered poor Boris [Johnson] to be a bit of a gom.
2019		A. Killilea Boyo-wulf at https://boyowulf.home.blog 14 Apr. 🌐 And from him came about all sorts of gurriers; gombeens and loolas and absolute gowls.
2021		P Howard Braywatch 2: ‘Albert Reynolds.’ ‘A gombeen and a back-stabber!’.