Mouse-like mammal (5)
I believe the answer is:
shrew
'mouse-like mammal' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for shrew that I've seen before include "eg Katharina" , "Mouse-like animal or scolding woman" , "Tamable woman?" , "insect eater" , "Woman who's assertive" .)