Where does “Olyroos” come from?

Olyroos (English) comes from English Olympic, from Ancient Greek Ὀλυμπικός, from Ancient Greek -ικός, from Ancient Greek -κός, from Proto-Indo-European -ḱos — -y, -ic.

Olyroos (English): The Australian Olympic soccer team

Definitions

The Australian Olympic soccer team

Ancestry of “Olyroos”, step by step

Olyroos traces back through two separate lines of ancestry.

via English Olympic

Step	Language	Word	Meaning
1	English	Olympic	Of or pertaining to the Olympic Games; Of or...
2	Ancient Greek	Ὀλυμπικός	Olympic
3	Ancient Greek	-ικός	of or pertaining to, in the manner of; -ic
4	Ancient Greek	-κός	forms adjectives with the sense of 'of or...
5	Proto-Indo-European	-ḱos	-y, -ic

via English kangaroos

Step	Language	Word	Meaning
1	English	kangaroos	plural of kangaroo; Third-person singular simple...
2	English	kangaroo	A member of the Macropodidae family of large...
3	Guugu Yimidhirr	gangurru	large grey or black kangaroo

Every word from Proto-Indo-European -ḱos →Every word from Ancient Greek -ικός →Every word from Ancient Greek -κός →