Notes:
Note: It is a possibility that the second element could be a cognate of the Welsh <moch> 'steep slope'.
There is no evidence that the second element has ever mutated following <tre> here or elsewhere. It is presumed that this is:-
1. To prevent double "v" following original <trev>.
2. To avoid confusion with <bogh> 'billy-goat' & <bogh> 'cheek'