Where does “-cosa-” come from?
-cosa- (English) comes from English icosa-, from Ancient Greek εἴκοσι, from Proto-Hellenic ewīkəti, from Proto-Indo-European wídḱm̥ti, from Proto-Indo-European dwidḱómt, from Proto-Indo-European déḱm̥t — ten.
Ancestry of “-cosa-”, step by step