Queen covered by country stars (4)
I believe the answer is:
ursa
'stars' is the definition.
(I've seen this before)
'queen covered by country' is the wordplay.
'queen' becomes 'r' (abbreviation for regina, e.g. in ER ).
'covered by' is an insertion indicator.
'country' becomes 'usa' (USA is an example).
'r' going within 'usa' is 'URSA'.
(Other definitions for ursa that I've seen before include "Constellation (Major or Minor)" , "(& 19 across) Plough constellation" , "(In the sky) Major or Minor" , "- Major, - Minor, prominent constellations" , "Major/Minor constellation" .)