joey · noun1
Unknown. Older and more general sources state that joey comes from an Australian Aboriginal language (cited as joè), but newer sources that focus on Australian English and Aboriginal languages say the origin is unknown. The Australian National Dictionary includes a sense of “young possum” with citations predating the earliest “young kangaroo” citations.
joey · noun2
From Joseph Grimaldi (1778–1837), a popular English entertainer.
joey · noun3
From British TV personality Joey Deacon (1920–1981), who was the focus of Blue Peter's 1981 charity campaign. The programme was aimed at children, who then picked the term up and used it as an insult.
joey · noun4
Said to have been named after Scottish politician Joseph Hume (1777–1855).
Joey · proper noun5
Etymology from Wiktionary, CC BY-SA 4.0.