Green’s Dictionary of Slang

(Aus./N.Z.) a handyman on a rural station, a roustabout.

1897		Worker (Brisbane) 4 Sept. 8/4: The ‘rouseabout,’ his willing slave, who's ever on the spot / To take the falling fleece away and fill his ‘water pot,’ / He sneeringly terms ‘loppy’ and a ‘leather-neck,’ and if / He doesn't ‘chuck’ himself about he swears to knock him stiff.
1900		Bulletin (Sydney) 18 Aug. 14/3: A good bushman rarely repeats himself either in swearing or slanging; for instance, the shearer terms the rouseabout variously a ‘loppy,’ ‘bluetongue,’ ‘wop-wop,’ ‘leather-neck,’ ‘crocodile,’ &c.
1908		Bulletin (Sydney) 1 Oct. 14/3: Th’ stumpy bloke showed ’s gums in a full-blown grin ’n’ said dead brisk, ‘Yours f’r a week, Loppy.’.
1933		Bulletin (Sydney) 8 Feb. 21: The loppies, who are meek and spry To shearers and the rest, Are perky chaps when I am by.
1945		Baker Aus. Lang. 62: A handyman on a station, otherwise called a [...] spoonbill, jack, loppy.
1964		H.P. Tritton Time Means Tucker 92: With only a couple thousand to go ‘Hughie’ answered the prayers of the loppies with a fairly heavy shower.