As described in historical dictionaries

Patronymica Britannica (1860)

MUS. It is curious that though Mouse does not appear to be an English surname, its Latin form, Mus, is so.

Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.


BritishSurnames.uk is a Good Stuff website.