Lift a lever to reset (8)
I believe the answer is:
elevator
'lift' is the definition.
('elevator' can be a synonym of 'lift')
'a lever to reset' is the wordplay.
'reset' indicates an anagram.
'a'+'lever'+'to'='aleverto'
'aleverto' with letters rearranged gives 'ELEVATOR'.
(Other definitions for elevator that I've seen before include "North American lift" , "what makes flight unnecessary" , "may give you a lift" , "An American lift in building" , "A lift in America" .)