“Enhanced” would be preferable (6)
I believe the answer is:
better
This could be a double definition.
'enhanced' is the first definition.
('better' can be a synonym of 'enhanced')
'preferable' is the second definition.
(thesaurus)
'would be' acts as a link.
This may not be correct. Some or all of it may belong to one of the definitions.
Can you help me to learn more?
(Other definitions for better that I've seen before include "Top" , "More able" , "Reformed" , "Gambler; more effective" , "'Discretion is the . . . . . . part of valour'" .)