G1 Cosmos' Greek name is Kυρίαρχος (Kyriarchos), which means "sovereign," and is where English gets the word kyriarchy ("a social system or set of connecting social systems built around domination, oppression, and submission") from.


(photo credit: F. Work)

Japanese: Adams (named after George Adamski)
Italian: Disco (meaning "saucer" or "disk")
Mandarin: Yǔzhòu Fēidié ("Space UFO"; which is silly, because the fact that we can identify Cosmos as a flying saucer means that he's an identified flying object)

Other languages' names for Cosmos are basically just their equivalent word for it...
Hungarian: Kozmosz
Portuguese: Cosmo
Russian: Kosmos

Somewhat funny that the Greek name for Cosmos isn't "Cosmos" considering that the word 'cosmos' itself comes from Greek! A direct English translation of "Cosmos" would be "Allworld."