Lift to reveal changes (8)
I believe the answer is:
elevator
'lift' is the definition.
('elevator' can be a synonym of 'lift')
'to reveal changes' is the wordplay.
'changes' is an anagram indicator.
'to'+'reveal'='toreveal'
'toreveal' with letters rearranged gives 'ELEVATOR'.
(Other definitions for elevator that I've seen before include "it's uplifting" , "may give you a lift" , "I go up" , "Lifting device" , "An American lift - going up?" .)