Runrig Fan is correct with the words "air uachdair a' ghoirtein". That would mean the "at the top" of the field. I simply copied the words I was given, but "uibhir", also spelled "uibhir", is a word for a number, a quantity - so doesn't make so much sense to me in this context. I would choose to sing "uachdair" instead of "uibhir".