Definition of robbo in US English:

robbo

noun

Australian
rare, slang
  • A horse and trap, especially one in a ramshackle condition; the driver or hirer of one of these. In extended use: an inferior, substandard, or decrepit person or thing.

Origin

Late 19th century; earliest use found in The Bulletin. Apparently from rob- (in the surname Robinson: see below) + -o.

Pronunciation

robbo

/ˈrɒbəʊ/