{ Jackaroo (?), n. Also Jackeroo}. [Jack + kangaroo.] A young man living as an apprentice on a sheep station, or otherwise engaged in acquainting himself with colonial life. [Colloq., Australia][Webster 1913 Suppl.]
Jackaroo, v. i. To be a jackaroo; to pass one's time as a jackaroo. [Colloq., Australia][Webster 1913 Suppl.]