Bear in the sky (4)
I believe the answer is:
ursa
'bear in the sky' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ursa that I've seen before include "(and 11 across) Pole Star constellation" , "Major/Minor constellation" , "(& 19 across) Plough constellation" , "and 18 Down: The Great Bear" , "'Major and Minor, constellations (4)'" .)