Green’s Dictionary of Slang

archie n.

also archy
[proper name, seen as upper-class]

(Aus.) a young station-hand, prob. a well-connected young man out from the UK.

[Aus]Baker Aus. Lang. 61: A young Englishman learning sheep or cattle farming [...] was a new chum, cadet and, later [i.e. late 19C], an archie.