Major or Minor constellation (4)
I believe the answer is:
ursa
'major or minor constellation' 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 "(& 19 across) Plough constellation" , "Bear (constellation)" , "stars" , "__ Minor, the Little Bear" , "It's both major anf minor overhead" .)