Green’s Dictionary of Slang

1. an unsophisticated, uncultured, philistine native-born Australian, who values material gain above everything else; personified as Tommy Geebung; also attrib.

1864		Launceston Examiner (Tas.) 5 Apr.3/1: TheThe sweetest natured native will object to being styled an ‘Acidulated Geebung’.
1881		Bulletin (Sydney) 8 Jan. 2/1: ‘Australian party’ does not necessarily mean ‘Australian born.’ That would be a real geebung notion.
1884		E.A. Martin Life and Speeches of Daniel Henry Deniehy 136: [...] more education, than [...] as a writer in the Southern Cross once called them, the Geebung Solicitors.
1895		Truth (Sydney) 24 Mar. 4/6: That our geebung aristocracy dearly love a lord is certain and nothing would please them better than to be allowed to make doormats of themselves for a real live lord to wipe his boots on.
1900		Bulletin (Sydney) 10 Mar. 15/1: What is the use of teaching Tommy Geebung that ‘saw’ is the past tense of ‘see,’ [...] when he has for his 12 years of life never heard or used anything but ‘I seen’ [...].
1914		Bulletin (Sydney) 22 Oct. 13/1: I forgot the Sydney people – / I forgot the big Importers – / I forgot the little Geebungs – / I forgot the Ma-State-Frighters!

2. a place-name for any out-of-the-way place; also attrib.

1896–9

H. Lawson ‘The Hero of Redclay’ in Roderick (1972) 303: A drunken doctor from a geebung town wasn’t of much account.

3. a gadget.

1890

‘Rolf Boldrewood’ Colonial Reformer II 60: Mr. Brigalow [...] produced some good whisky, and with an invention of his own, called a geebung, a fair imitation of soda water was concocted.