Green’s Dictionary of Slang

1. (also three be two) a Jew.

1921		N&Q 12 Ser. IX 346: Four-by-Two. [...] Used also to express a ‘Jew’.
1936		J. Curtis Gilt Kid 69: ‘I had to order a sandwich for you.’ [...] ‘That’s all right so long as it’s not ham. [...] I’m a four-be two, you see.’.
1943		M. Harrison Reported Safe Arrival 10: Harry was a Jew. In his own phrase: a ‘tin-lid.’ Otherwise, a ‘four-by-two,’ a ‘Kangaroo,’ or a ‘five-to-two’.
1943		R. Llewellyn None But the Lonely Heart 265: Don’t take long to wipe up a couple of Three Be Twos, do it?
1959		J. Gosling Ghost Squad 24: Thieves’ argot, spoken properly, is a foreign language which needs to be learned [...] Among the words and phrases derived from rhyming slang are: [...] Sarah Soo, Four-by-two or Kangar (Kangaroo) means a Jew.
1963–74		B. Humphries Barry McKenzie [comic strip] in Complete Barry McKenzie (1988) 78: Lew Silver, a well known artistic four by two.
1967		J. Wynnum I’m a Jack, All Right 128: Joe was munching industriously at a huge piece of pork. ‘I’d have hated to have been born a four-by-two and missed out on this’.
1979		R. Barker Fletcher’s Book of Rhy. Sl. 27: A rich four-by-twoish merchant.
1980		Barltrop & Wolveridge Muvver Tongue 53: Jews are [...] four-by-twos.
1983		R. Aven-Bray Ridgey-Didge Oz Jack Lang 28: Fourbies (4 x 2) [...] Jew.
1998		P. Doyle (con. late 1950s) Amaze Your Friends (2019) 22: ‘He’d be of the Jewish faith? [...] your four-by-two tends to be skilled at this sort of thing’.
2024		J. Meades Empty Wigs (t/s) 842: ‘Yids. Four by twos. Oven dodgers. Four wheel -’.

2. (usu. Aus./N.Z.) a prison warder [= screw n.¹ (2c)].

1979		R. Barker Fletcher’s Book of Rhy. Sl. 24: Who are you calling a four-by-two?
1982		G. Newbold Big Huey 248: four-by-two (n) Prison officer.
1983		R. Aven-Bray Ridgey-Didge Oz Jack Lang 28: Fourbies (4 x 2) Screw (warder).
1990		Tupper & Wortley Aus. Prison Sl. Gloss. 🌐 Four by two. A prisoner officer. Rhyming slang for screw [...] Sometimes just fourbees.
1996		P. Howard The Joy (2015) [ebook] The four-by-twos do their best but they can’t watch everyone twenty-four hours a day.
2001		D. Looser Boobslang [U. Canterbury D.Phil. thesis] : four-by-two (also fourby) n. a prison officer.