Lever altered, readjusted (7)
I believe the answer is:
treadle
'lever' is the definition.
(treadle is a kind of lever)
'altered readjusted' is the wordplay.
'readjusted' indicates anagramming the letters.
'altered' is an anagram of 'TREADLE'.
(Other definitions for treadle that I've seen before include "Foot-operated lever" , "driving mechanism" , "Alerted (anag)" , "Foot-pedal" , "Foot lever working machine" .)