Manx fys

← Proto-Celtic *wissus (inherited)

← Proto-Indo-European *weyd- (root)

← Proto-Indo-European *wéydtus (inherited)

← Proto-Indo-European *weyd- (mention)

← Old Irish fis (inherited)

← Old Irish fius (mention)

→ Manx co-yssaght (confix)

→ Manx neufys (prefix)