c.1425, possibly from Anglo-Fr. *dormouse
"tending to be dormant" (from stem of dormir
"to sleep," see dormer
), with the second element mistaken for mouse,
or from a M.E. dial. compound of mouse
and M.Fr. dormir.
The rodent is inactive in winter. Fr. dormeuse,
fem. of dormeur
"sleeper" is only attested from 17c.