Mummy bear pours away just a bit (4)
I believe the answer is:
ursa
'mummy bear' is the definition.
('bear' in Latin)
'pours away just a bit' is the wordplay.
'just a bit' indicates the answer is hidden within the clue.
'URSA' is hidden within 'pours away'.
(Other definitions for ursa that I've seen before include "Major and Minor, the Bear constellations" , "It's both major anf minor overhead" , "The Major one is the Plough" , "Major/Minor constellation" , "Latin for the Great Bear, . . . . Major" .)