Reveal changes about to lift (8)
I believe the answer is:
elevator
'lift' is the definition.
(synonyms)
'reveal changes about to' is the wordplay.
'changes' is an anagram indicator.
'about' is an insertion indicator.
'reveal' with letters rearranged gives 'elevar'.
'elevar' enclosing 'to' is 'ELEVATOR'.
(Other definitions for elevator that I've seen before include "Lift - granary - aircraft control" , "Cage that is raised and lowered mechanically in a vertical shaft" , "A lift in America" , "An American lift - going up?" , "I go up" .)