Little Bear to roam ruins, somehow (4,5)
I believe the answer is:
ursa minor
'little bear' is the definition.
(synonyms)
'roam ruins somehow' is the wordplay.
'somehow' indicates anagramming the letters.
'roam'+'ruins'='roamruins'
'roamruins' with letters rearranged gives 'URSA MINOR'.
'to' acts as a link.
(Other definitions for ursa minor that I've seen before include "Group appearing nightly" , "Group of stars" , "Paddington, say" , "Paddington, for example" , "Star group" .)