Green’s Dictionary of Slang

1. a cook, esp. in an institution, mining camp or farm.

1905		Duke Tritton’s Letter n.p.: No doubts about it, my Mary is a bottling Babbling Brook.
1918		Aussie (France) 6 Aug. 1/1: What’s this the Babbling Brook has given me – tea or stew?
1918		Kia Ora Coo-ee 15 Sept. 14/3: Cooks range from the grease-besmudged ‘babbler’, who dishes up a monotonous succession of ‘teas straight’, bad language and an occasional stew, to the natty, smart-looking chef.
1924		(con. WWI) A.G. Pretty Gloss. of Sl. [...] in the A.I.F. 1921–1924 (rev. t/s) n.p.: babbling brook or Babbler. An Army Cook. Originated in the rhyming slang as ‘Babbling Brook,’ one of the few terms so originated that were subjected to further adaptation.
1925		(con. WWI) Fraser & Gibbons Soldier and Sailor Words 13: Babbler, The: An Army Cook. A contraction of the rhyming slang word Babbling Brook.
1930		(con. 1914–18) Brophy & Partridge Songs and Sl. of the British Soldier 96: Babbling brook. — Cook.
1930		Leader-Post (Regina, Saskatchewan) 8 Aug. 29/3: [The cook] is known variously as ‘Cooky,’ ‘The Poisoner,’ ‘The Doc,’ ‘The Babbling Brook’.
1932		(con. WWI) L. Mann Flesh in Armour 115: ‘I bet the babblers aren’t up yet’.
1936		Townsville Daily Bull. 27 Aug. 5/2: Bernie, the Western drovers cook / Who was known from the Gulf to Brisbane, as the / ‘Battling Babbling Brook’.
1944		L. Glassop We Were the Rats 114: They reckon the babbling brook’s done some rissoles.
1953		T.A.G. Hungerford Riverslake 122: ‘I hear a few babblers managed to get in,’ Murdock sneered.
1965		B. Wannan Fair Go, Spinner 67: The shearing gang in those days took their own ‘babbler’.
1968		J. Alard He who Shoots Last 96: Don’t forget ta tell da babblin’ brook.
1972		Dodson & Saczek Dict. of Cockney Rhy. Sl.
1984		J. Carson in Ammon Working Lives 150: Wake the ‘babbling brook’ and get him to pour some oil in it.
1988		McGill Dict. of Kiwi Sl. 12/1: babbler cook; rhyming slang ‘babbling brook / cook’, used by shearing gangs and WWI Anzacs. NZA.
1990		Tupper & Wortley Aus. Prison Sl. Gloss. 🌐 Babbling brook. Rhyming slang for (prison) cook.
1999		G. Seal Lingo 60: The troops preserved and extended such terms as [...] babbler (from babbling brook, rhyming slang for cook used by shearers and other outback workers).
2002		Pete’s Aussie Sl. Home Page 🌐 babbling brook, babbler: a cook.
2003		McGill Reed Dict. of N.Z. Sl. [as cit. 1988].
2021		Betoota-isms 242: ‘You’ve gotta try the new cutlets on the menu at the Rissole, they’ve just hired a new Babbling Brook’.

2. a criminal, a villain.

1928		E. Booth ‘Language of the Und.’ Amer. Mercury May.
1936		Mencken Amer. Lang. (4th edn) 578: Down to a few years ago, for some reason unknown, Cockney rhyming cant, supposed to have come in by way of Australia, was very popular among American thieves. It consists largely of a series of rhyming substitutions, e.g., [...] babbling brook for crook.
1949		Monteleone Criminal Sl. (rev. edn) 13: babbling brook A crook.
1960, 1975		Wentworth & Flexner DAS 11/2: babbling brook, babbler – crook.
1963		L.F. Freed Crime in S. Afr. 106: When he expresses pity for ‘a babbling brook’, he is being sorry for a crook.
1969		S.T. Kendall Up the Frog.
1989		J. Morton Lowspeak 15: Babbler – thief.
1999		R. Walton ‘Cockney Jack’ 🌐 Jack turned toward the cries, just in time to see a babbling brook dash out of a bakery carrying a bag of bees and honey.
2002		B. Kirkpatrick Wicked Cockney Rhy. Sl.

3. (US campus) a mediocrity.

1932

J.L. Kuethe ‘Johns Hopkins Jargon’ in AS VII:5 329: babbler—not a likable fellow; a mediocre person.