The word for hat or cap in Italian is cappello (masculine, plural: cappelli). It derives from the Latin cappellus which in turn comes from the word cappa meaning hood.
Could it be Upper Bettws in dog-Latin?
I’m not really convinced by the above suggestion.
Cappella (meaning ‘chapel’) is a standard word in church registers.
Bettws (meaning ‘house of prayer’) is a very common place-name (for lots of examples, see
https://www.british-history.ac.uk/topographical-dict/wales/pp81-88#h3).
‘Upper’ would normally be written out in English. If the register is in Latin, you would expect something like ‘Sup.' or ‘Superior’. But that’s not to say your suggested location of
Upper Bettws is wrong (assuming it was in existence at the date of this register?)
But any chapel-of-ease might be known locally within its own parish as
Cappella Bettws, or some form of that name. So I think you need to be looking in the parish of Abergavenny, on the basis that if it was further afield it would probably be designated with another parish name.
Just my thoughts.
