Show a lever moving (6)
I believe the answer is:
reveal
'show' is the definition.
(I know that reveal is a type of show)
'a lever moving' is the wordplay.
'moving' indicates anagramming the letters.
'a'+'lever'='alever'
'alever' anagrammed gives 'REVEAL'.
(Other definitions for reveal that I've seen before include "Make known, expose" , "Expose, divulge" , "Remove cover, unveil" , "Spill beans" , "'Disclose, divulge (6)'" .)