Green’s Dictionary of Slang

1. (Aus./N.Z.) mad, insane; usu. in phr. go troppo .

1941		Army News (Darwin, NT) 4 Dec. 5/2: There is such a preponderance of women to men that even the attentions of a ‘troppo’ aviator from Darwin were not unkindly received.
1944		Ellesmere Guardian (Canterbury) 8 Feb. 2/2: This is no gibberish, nor is it a sign that the speakers are ‘troppo’.
1946		R. Rivett Behind Bamboo 399/2: Troppo, mad, sunstruck, weakminded, affected by captivity.
1948		S.L. Elliott Rusty Bugles I i: A bloke’ud have to go troppo in a hut full of drongoes like youse.
1951		Cusack & James Come in Spinner (1960) 263: ‘Not but what I won’t like the place a lot better when your Yankee friends have finished using it as first base.’ ‘Snaky?’ she asked, looking at him judicially, ‘or just gone troppo?’.
1954		(con. 1940s) E. Lambert Veterans 105: We relieved our wound-up minds with a sort of desperate, manufactured humour, even feigning madness [...] ‘Troppo acts’ we called them.
1960		J. Walker No Sunlight Singing (1966) 53: They had been told that the man in charge of the bore was ‘troppo.’.
1963		(con. 1944) L. Glassop Rats in New Guinea 197: My God, I thought, I’m going troppo. I’m even smoking without cigarettes now.
1975		K. Willey Ghosts of the Big Country 164: Mr. Smith said, he himself had several times verged on going ‘troppo.’.
1986		C. Bowles G’DAY 98: If you also suspect that this condition is due to long periods of isolation or too much sun, you’ll say they’ve ‘gone troppo’ .
1988		McGill Dict. of Kiwi Sl. 114/2: troppo displaying mental unsteadiness, often in phr. gone troppo; Anzac word for WWII Pacific theatre servicemen too long in the tropics and badly in need of repatriation.
1998		P. Doyle (con. late 1950s) Amaze Your Friends (2019) 88: ‘He’s in hospital.’ [...] ‘Another one gone troppo’.
1999		Observer Mag. 15 Aug. 20: Perhaps she went troppo when she was [...] young and wild.
2000		Indep. on Sun. 5 Mar. 32: Aussies go troppo for the pokies.
2003		McGill Reed Dict. of N.Z. Sl. [as cit. 1988].
2019		P. Temple ‘High Art’ in The Red Hand 17: ‘Steady on, old boot [...] You may have gone troppo’.
2021		P. Papathanasiou Stoning 178: ‘[I]n this heat, people tend to go a little troppo’.

2. in attrib. use of sense 1.

1945

Morn. Bulletin (Rockhampton, Qld) 8 May 6/2: Witha shock it dawned on me — I was in the ‘Troppo’ Ward!