Where does “kerroo” come from?
kerroo (Manx) comes from Old Irish cethramad, from Proto-Celtic kʷetwariyos, from Proto-Indo-European kʷturyós, from Proto-Indo-European kʷetwóres, from Proto-Indo-European kʷe- — and.
kerroo (Manx): fourth; quarter, fourth
Ancestry of “kerroo”, step by step