Green’s Dictionary of Slang

1. a fool, a simpleton.

1895		Coventry Eve. Teleg. 8 Oct. 4/2: No, Gubbins, you will never be a brainworker.
1904		Kipling ‘Their Lawful Occasions Pt I’ in Traffics and Discoveries 105: Disregarding the inventions of the Marine Captain, whose other name is Gubbins, let a plain statement suffice.
1925		(con. WWI) Fraser & Gibbons Soldier and Sailor Words 112: Gubbins, A: A fool.
1955		‘E.C.R. Lorac’ Ask a Policeman 25: If we only get these old gubbinses out I could let the rooms proper [OED].

2. an indefinite n. for any nameless object.

1921		N&Q 12 Ser. IX 503: Gubbins. Stuff, personal belongings, stores, etc.
1925		(con. WWI) Fraser & Gibbons Soldier and Sailor Words 112: Gubbins: Mere stuff. Trash. Anything of no value.
1944		P. Kendall Dict. Service Sl. n.p.: gubbins . . . soiled dressings.
1985		J. Sullivan ‘Strained Relations’ Only Fools and Horses [TV script] You get a build-up of pressure and the safety valves ain’t working – bang – the whole gubbins explodes!
1999		Guardian Guide 17–23 July 32: Dion has got a team of assistants to help him trawl the banks of the Thames for interesting gubbins.
1999		Observer Mag. 25 July 49: The ratio of cabin room to mechanical gubbins is much like that of a Mini.
2000		M.J. Trow Lestrade and the Gift of the Prince 37: If I were to take scrapings then and heat them over a bunsen burner, the whole gubbins would solidify.
2013		K. Sampson Killing Pool 286: I got all the gubbins here if you want a cup [of coffee] you could taste.