The advantage of adjustable seats (5)
I believe the answer is:
asset
'the advantage' is the definition.
(thesaurus)
'adjustable seats' is the wordplay.
'adjustable' indicates an anagram.
'seats' is an anagram of 'ASSET'.
'of' acts as a link.
(Other definitions for asset that I've seen before include "Valuable item" , "virtue" , "Boon" , "Item conferring advantage" , "Something of value, worth having" .)