in the 1750's Manx would have been dominant in the northern parishes - all vicars and parish clerks would speak Manx (probably as their first language) - the pias is almost certainly a transcription error for nias (possibly my error but as I transcribe yr by yr I doubt if I would have made same error twice - however by 1911 the copyist probably did not have Manx and thus would not question it) - judging from Kneen's entry and his Manx was pretty good (!!) he too was puzzled by derivation