Green’s Dictionary of Slang

1. a ‘bad lot’, a socially unacceptable person, also attrib.

1896		Windsor Mag. 4 163: My aunt said the other day that she didnt know what a rotter was.
1899		E.W. Hornung Amateur Cracksman (1992) 34: Then we’d better get back and make sure of the other rotter.
1901		Marvel XV:387 Apr. 2: Take that, you blooming rotter!
1904		Sun. Times (Perth) 13 Mar. 8/2: The Adelaide Club, which is composed of a queer collection of snobs, rotters, and schoolteachers.
1909		E. Glyn Three Weeks 41: ‘Uncle Hubert is a rotter!’ ‘A — rotter?’ inquired the lady. ‘And what is that?’.
1910		W. Sickert Art News 10 Feb. 144: So-and-so is a rotter, but he can paint.
1910		Sun. Times (Perth) 6 Feb. 2nd sect. 4/6: ‘Rotter’ and ‘mongrel’ — the latter word, it was subsequently explained, being used strictly in a political sense — were the courteous terms slung at Prime Minister Deakin.
1911		Gem 16 Sept. 6: He can tell a decent chap from a rotter at once.
c.1912		Powell & Arthurs [perf. Marie Lloyd] Three Ages of Women 🎵 She calls him a pitiless bald-headed bore / Conceited and vain when a woman is near / A rotter with only one single idea.
1913		Truth (Sydney) 25 May 11/3: Well, what I’m agoin to tell you / Are about a rotter bloke, / Who ain’t fit for nothin' better / Than the hangman’s rope to choke.
1919		Marvel 3 Mar. 6: He has the right to stand up for a third-rate rotter like Donbrook, if he’s ass enough to do it.
1924		P. Marks Plastic Age 319: I hate a prig, Cynthia, like the devil, but I hate a rotter even more.
1939		J. Campbell Babe is Wise 95: Turning dog on me, are you, eh, you little Yiddish rotter!
1942		A. Christie Body in the Library (1959) 157: Rosamund had married a rotter.
1953		A. Buckeridge Jennings’ Diary 15: Don’t be such a rotter, Venables!
1961		B. Crump Hang On a Minute, Mate (1963) 176: He’s a fair dinkum rotter.
1968		A. Burgess Enderby Outside in Complete Enderby (2002) 280: You filthy thing. You sexless rotter.
1973		A. Bennett Habeus Corpus Act II: You’re a stinker, Arthur Wicksteed. [...] A rotter.
1983		(con. 1940s) D. Nobbs Second From Last in the Sack Race 66: Patrick was a rotter.
1990		R. Malan My Traitor’s Heart (1991) 61: She married a rotter who abandoned her with six young children.
1990		Dennis the Menace Annual 32: You little rotter!
1999		R.G. Barrett Wind & Monkey (2013) [ebook] ‘Me and Price sold him a yearling. Price got his end. But I still haven’t got mine.’ ‘The rotter,’ said Les.
2000		Indep. on Sun. Rev. 19 Mar. 21: Calling the old hack a ‘dirty sod’ and ‘a fucking rotter.’.

2. (Aus.) a poor performance.

1905		Sun (Kalgoorlie, WA) 12 Mar. 2/5: Industry, Tom Garvey's bay, ran a real rotter in the Hampton Hurdles [...] ‘I thought you said he could jump,’ asked his rider [...] ‘Why, the blanker ran through every hurdle’.
1913		Port Pirie Recorder (SA) 28 May 3/2: I think Wassail will beat this pair in the Cup. Hopwood’s horse ran a real ‘rotter’ in the Adelaide Cup, but he showed that that form was all wrong by taking the S.A.J.C. Handicap.

3. (Aus.) an unpleasant experience.

1906

Truth (Brisbane) 22 Apr. 6/3: ‘Oh, God! old girl I’ve had a rotter of a day, never backed a bally winner’.

4. (Aus.) a half-trained horse.

1911		Sun. Times (Perth) 1 Oct. 14/3: Magas ran like a real rotter at Canning Park; finishing last of the bunch.
1914		Bulletin (Sydney) 13 Aug. 36/1: The National fields, in the first place, are more or less lumbered with rotters or half-trained nags.