Tessa returned saleable item (5)
I believe the answer is:
asset
'saleable item' is the definition.
'asset' can be an answer for 'item' (I have seen 'Item of value' mean 'asset' so perhaps 'item' could also mean 'asset'). I am not certain of the 'saleable' bit.
'tessa returned' is the wordplay.
'returned' says the letters should be written in reverse.
'tessa' reversed gives 'ASSET'.
Can you help me to learn more?
(Other definitions for asset that I've seen before include "Something that's worth having" , "Strong point" , "Valuable person" , "Plus point" , "Seats (anag.)" .)