Green’s Dictionary of Slang

1. (also old lagger) a habitual prisoner, a recidivist, orig. a returnee from transportation to Australia.

1812		Vaux Vocab. of the Flash Lang. in McLachlan (1964) 255: old lag a man or woman who has been transported, is so called on returning home, by those who are acquainted with the secret.
1856		Age (Melbourne) 13 Dec. 5/2: An old lag from the otherside, where he had done a long sentence from home.
1857		Bell’s Life in Sydney 7 Feb. 3/3: If you are a son-in-law of that old lag [...] don’t come here to annoy me.
1867		Queenslander (Brisbane) 15 June n.p.: Lawyers and ‘old lags’, doctors and ‘Pentonvilles’ [...] are to be seen ‘on the wallaby’.
1877		Five Years’ Penal Servitude 59: The old prisoner who had acted as barber [...] was an ‘old Lag’.
1882		Sydney Sl. Dict. (2 edn) 6: Old Hand, or Lag - An old convict (one who was not a passenger, but who ‘come’).
1886		W. Newton Secrets of Tramp Life Revealed 3: We also have the returned convict, or as he is termed in their vocabulary, ‘Old Lag’.
1893		J. Demarr Adventures in Aus. 44: A man who had been transported, was said to have been ‘lagged,’ and a transport was an ‘old lag’.
1898		Binstead & Wells A Pink ’Un and a Pelican 235: [chapter heading] The doughty men of the East — An old lag — A counterfeit coiner.
1900		Marvel XIV:344 June 2: You lazy, hulking, cunning old lags!
1902		Cheltenham Chron. 4 Jan. 5/5: The mixing up of boys, debtors, and ordinary prisoners — some of whom may be old ‘lags’ — in the same ward.
1924		S. Scott Human Side of Crook and Convict Life 19: Two old ‘lags’ were unconcernedly discussing the Derby.
1928		N.Z. Truth 17 May 6/3: Some of the best tributes to him [i.e. a detective] have come from old lags.
1936		J. Curtis Gilt Kid 198: Nobody’ll worry two damns about how an old lag like you came to fall into the Drink.
1941		V. Davis Phenomena in Crime 52: Sharpe [...] recognised it as an ‘old lag’s portmanteau’.
1944		Sun (Sydney) 10 Nov. 2/1: ‘I’m an old lag meself. I’ve been in and out of boob since I was a kid’.
1949		Wodehouse Mating Season 171: I am mistaken in supposing that this old lag is about to resume his life of crime.
1954		J. Phelan Tramp at Anchor 85: The crushing misfortune of my being theoretically made into a recidivist, an old lag.
1982		G. Newbold Big Huey 74: [A] lot of the old lags at Paremoremo will complain that the old rules are breaking down now.
1984		B. Ellem Doing Time 192: lagger: an old prisoner who has done several sentences or laggings; he is usually referred to as an ‘old lagger’.
1994		B. Payne Poor Behaviour 50: ‘You only been here ten minutes so take a tip from an old lagger. Keep your mouth shut and mind your own business or you'll do a hard lag’.
2000		J.J. Connolly Layer Cake 287: An old lag used to tell him that for a story to be truly convincing it must contain inconsistencies.
2001		D. Looser Boobslang [U. Canterbury D.Phil. thesis] : old lag (also old lagger n. 1 a recidivist, a repeat offender, an inmate who has been in and out of prison for many years [...] These inmates are often highly respected .
2006		B. Matthews Intractable [ebook] Parramatta became a traditional recidivist prison used to house habitual criminals and old lags.
2011		J.J. Connolly Viva La Madness 73: He’s up early, six or half past. Old lag’s thing that.

2. in attr. use of sense 1.

1962

in K. Richards Life (2010) 78: Of course’ve still got the old Lags here y’know Cliff Richard, Adam Faith and [...] Shane Fenton.

3. (N.Z. prison) an inmate serving a long or life sentence, one who has served the bulk of that sentence.

2001

D. Looser Boobslang [U. Canterbury D.Phil. thesis] 103/2: old lag2 an inmate serving a long or life sentence, esp. one who has already served a considerable amount of that sentence .