Green’s Dictionary of Slang

troppo adj.

[SE tropical, i.e. the effects of the heat, + -o sfx (4)]

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

[Aus]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.
[NZ]Ellesmere Guardian (Canterbury) 8 Feb. 2/2: This is no gibberish, nor is it a sign that the speakers are ‘troppo’.
[Aus]R. Rivett Behind Bamboo 399/2: Troppo, mad, sunstruck, weakminded, affected by captivity.
[Aus]S.L. Elliott Rusty Bugles I i: A bloke’ud have to go troppo in a hut full of drongoes like youse.
[Aus]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?’.
[Aus](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.
[Aus]J. Walker No Sunlight Singing (1966) 53: They had been told that the man in charge of the bore was ‘troppo.’.
[Aus](con. 1944) L. Glassop Rats in New Guinea 197: My God, I thought, I’m going troppo. I’m even smoking without cigarettes now.
[Aus]K. Willey Ghosts of the Big Country 164: Mr. Smith said, he himself had several times verged on going ‘troppo.’.
[Aus]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’ .
[NZ]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.
[UK]Observer Mag. 15 Aug. 20: Perhaps she went troppo when she was [...] young and wild.
[UK]Indep. on Sun. 5 Mar. 32: Aussies go troppo for the pokies.
[NZ]McGill Reed Dict. of N.Z. Sl. [as cit. 1988].

2. in attrib. use of sense 1.

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