Green’s Dictionary of Slang

1. (orig. Aus./N.Z.) a general term of abuse, a rogue, an eccentric; thus ratbaggery, acting in such a manner.

1858		O.W. Holmes Autocrat of the Breakfast Table 337: The Rat-bag has stolen your piece, after carefully scratching your name out.
1890		Quiz (Adelaide) 1 Aug. 2/2: The Imperial ratbag amongst us brings these insults upon us [AND].
1926		Mirror (Perth) 6 Nov. 12/3: His Honor: He’s a rat-bag! Witness: ’Oo are you callin’ a rat-bag.
1937		‘William Hatfield’ I Find Aus. 138: ‘You brought one rat-bag in,’ said Ewens to me, ‘so now do me a favour by taking one off my hands.’ [OED].
1940		E. Curry Hysterical Hist. of Aus. 167: Time, my dear old ratbags, will not permit me.
1941		K. Tennant Battlers 96: ‘I tell you you’re a rat-bag,’ Dick Tyrell was declaring offensively to Adelaide.
1941		Mirror (Perth) 1 Nov. 4/4: Jackel had called his sister a ‘ratbag’. By ‘ratbag’ I understood he meant she was an unchaste girl.
1950		(con. 1936–46) K.S. Prichard Winged Seeds (1984) 31: Tom and Decker were out all night [...] tryin’ to make the rat-bags who’d started the riotin’ listen to reason.
1959		Galton & Simpson ‘Hancock’s Half-Hour’ ser. 5 [radio ascript] Step down, you ratbag.
1965		W. Dick Bunch of Ratbags 27: A lot of wheat lay on the floor of the wheat trucks, owing to the rats having chewed the bottom out of the bags. These bags with the rat-chewed holes in the bottom were known originally as ‘ratbags’. But this word had been adopted as a slang word to describe any person who was empty-headed or an idiot. ‘Oh, he’s just a bloody ratbag, that bastard, that’s all he is,’ was our popular saying.
1974		P. Larkin ‘The Life with a Hole in it’ in Coll. Poems (1988) 202: What the old ratbags mean / Is I’ve never done what I don’t.
1972		A. Chipper Aussie Swearers Guide 67: Ratbaggery, anything un-Aussie or un-normal.
1979		D. Maitland Breaking Out 66: ‘Ratbags!’ Bert bawled. ‘Dead-shits, the bloody lot of you!’.
1981		G. Johnston Fish Factory 148: No more beer for these two ratbags.
1981		Aus. Women’s Wkly 20 May 129s/2: A ratbag is off-centre, a bit eccentric and a bit dotty.
1992		K. Lette Llama Parlour 61: You’re the rudest sleaze-schmucko-ratbag I’ve ever met.
1996		J. Byrell Lairs, Urgers & Coat-Tuggers 173: [S]o cocksure was the royal ratbag that he had his emissaries toddling all over London placing poultices on My Babu.
1998		I. Welsh Filth 204: Lennox has taken the hump big-time, the moosey-faced rat-bag.
2000		R.G. Barrett Leaving Bondi (2013) [ebook] Those ratbags were just about to cut that poor girl’s throat.
2003		McGill Reed Dict. of N.Z. Sl. 170: ratbag/ratter 1. Nasty, eccentric, unreliable, troublesome, uncouth or worthless person, likely to exhibit ratbaggery or unacceptable or eccentric behaviour. 2. Engaging rogue or unconventional fellow, often an old ratbag.
2005		M.B. ‘Chopper’ Read Chopper 4 5: Piss Ant may have been a tough, bad-tempered ratbag, but he loved his old grandfather.
2016		D. Whish-Wilson Old Scores [ebook] ‘Never picked you for a ratbag, Swann’.

2. (US) an unpleasant situation or job.

1962

C. Clausen I Love You Honey, But the Season’s Over 48: Sometimes [...] a man would announce that he was ‘gonna quit this ratbag for good’.

3. (US) a slum.

1985

T. Wolff ‘Leviathan’ in Back in the World 187: ‘[H]e was living in this ratbag on Post Street. All he had in there was lawn furniture’.