Eve's tempter repents going astray (7)
I believe the answer is:
serpent
'eve's tempter' is the definition.
(I've seen this before)
'repents going astray' is the wordplay.
'going astray' indicates anagramming the letters.
'repents' anagrammed gives 'SERPENT'.
(Other definitions for serpent that I've seen before include "Venomous snake" , "Malicious person" , "Early wind instrument" , "Present (anag.)" , "exhibit at zoo" .)