Better reinforce lift (7)
I believe the answer is:
enhance
This clue is a triple definition!
'better' is the first definition.
(to enhance something is to make it better)
'reinforce' is the second definition.
(thesaurus)
'lift' is the third definition.
(lift can mean to enhance or improve)
(Other definitions for enhance that I've seen before include "Improve, make more attractive" , "improve things" , "Increase in power" , "Make better or more attractive" , "Make even better" .)