Tessa returned something valuable (5)
I believe the answer is:
asset
'something valuable' is the definition.
(I've seen this before)
'tessa returned' is the wordplay.
'returned' shows that the letters should be reversed in order.
'tessa' backwards is 'ASSET'.
(Other definitions for asset that I've seen before include "Plus point" , "Anything of value" , "Item well worth having" , "Item conferring advantage" , "A thing of value" .)