Cue the tale of Moses and the Exodus from Egypt. Moses being part of the outed Akhenaten family. The name Moses is in fact a good Egyptian name meaning “son.” It’s a common element in the names of many pharaohs, such as Tuthmoses and, most famously, Ramesses (“son of Ra”).
Sounds distinctly fishy in line with most seemingly rational etymologies of names/places. Thing is, 'mos/s' 'mus/a' and so forth is very common, so common in fact that it's either "from Latin [mosa]" or "Celtic".
The Megalithic associations are intriguing. For instance, the suggested etymology to do with mazes:
Etymology: < Middle French muce, musse, mouce hiding place, secret place (1190 in Old French as muce; only from 1561 in spec. sense 1a; French regional (central and western) musse hiding place, hole in a hedge) < mucier, mucer to hide, conceal oneself (second half of the 12th cent.; compare Anglo-Norman muscier, muscer, mucier, etc.; also Italian (regional) mucciare, muccire to flee) < an unidentified reflex of the Celtic base of Early Irish múch smoke, Welsh mwg smoke, which in turn is related to the Germanic base of smoke v. Compare mitch v., muset n.1 Compare slightly earlier maze n.2 and discussion at that entry.
which in turn leads to hedge-gap/tunnel, track leading to rabbit snares
A gap in a fence or hedge through which hares, rabbits, etc., pass, esp. as a means of escape; (also) a man-made track or tunnel for leading hares, rabbits, etc., into a trap.
There's a place at St Michael's Bay called Mousehole, pronounced Meusel/Mosel like the river(s). According to Wiki Maas, the Dutch version of Meuse, is their nickname for 'Thomas' which reminds me of an AE discussion about the Thames and various Thomases.