Green’s Dictionary of Slang

1. to act noisily.

1828

‘Humours of Glasgow Fair’ [broadsheet ballad] Sich a crowd they could scarcely get through, / Fiddles, Trumpets and Organs, a’ bumming. / O sirs! what a Huly Baloo.

2. to boast, to brag; thus bum up v., to praise, to promote; thus bumming adj., boastful.

1894		Truth (Sydney) 24 June 1/4: There’s Squills, to whom no wise men go / [...] / Who’s far less of a medico / Than bumming politician.
1908		L. Doyle Ballygullion 28: The father an’ mother, too, was always bummin’ up Pether’s money.
1917		A.G. Empey Over the Top 116: I don’t like bumming up my own battery, but we had a record in the Division for direct hits, and our boys were just pining away for a chance to exhibit their skill in the eyes of Fritz.
1925		L. Doyle Dear Ducks 98: The two of them talked half the night. But Leonard fair out-bummed Peter. [Ibid.] 229: His pig was doin’ well, an’ the whole town of Ballygullion knew it, for wee Jones was a bumming kind of crather.
1937		J. Curtis There Ain’t No Justice 142: I don’t see what you’re bumming your chat about.
1956		J. Curtis Look Long Upon a Monkey 72: Even if your cousin’s the law or a judge, that ain’t buggerall to bum your chat about. Very opposite, if you ask me. You want to be properly ashamed of it.
1962		B. McGhee Cut and Run (1963) 35: You’re no’ gonny let they Soo’ Side bastarts go aboot bummin’ that they chased ony o’ the Carlton crowd, are ye?
1967		C.P. Taylor Happy Days Are Here Again (1968) 151: Donovan thinks he’s knows everything! You’re always bumming up Donovan to me!
1970		S. O’Faoláin Stories of Seán O’Faoláin 280: My ould divil of a tailor is forever and always talkin’ about ‘um [...] Bummin’ and boashtin’ he is from morning to night .
1973		(con. mid-1960s) J. Patrick Glasgow Gang Observed 231: Bummin’ – boasting.
1976		(con. 1930s) J. Wolveridge Ain’t it Grand 65: There was a film called ‘Bank Holiday’ which was bummed up as being about ordinary people but it was full of the usual phoney Cockneys.
1997		Share Slanguage.

3. (US) to abuse verbally.

1985

‘Jennifer Blowdryer’ Modern English 8: bumming (v): On somebody means insulting them.