A second television, plus point (5)
I believe the answer is:
asset
'plus point' is the definition.
(I've seen this in another clue)
'a second television' is the wordplay.
'second' becomes 's' (common abbreviation).
'television' becomes 'set' (television set).
'a'+'s'+'set'='ASSET'
(Other definitions for asset that I've seen before include "Valuable item" , "Item well worth having" , "Item of property" , "Plus point" , "valuable sort" .)