Bear in constellation names (4)
I believe the answer is:
ursa
'bear in constellation names' 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 "'Major and Minor, constellations (4)'" , "The Major one is the Plough" , "__ Minor, the Little Bear" , "stars" , "(& 19 across) Plough constellation" .)