Contribution from author Sewell, such as 'Black Beauty' (5)
I believe the answer is:
horse
'black beauty' is the definition.
(thesaurus)
'contribution from author sewell such' is the wordplay.
'contribution from' says the answer is hidden in the clue (the concealed answer 'contributes' to the clue).
'HORSE' is hidden in the letters of 'author sewell such'.
'as' is the link.
(Other definitions for horse that I've seen before include "eg Shire" , "bay, perhaps" , "Equine quadruped" , "Might one be up on this" , "Suffolk punch" .)