She tempts one again into wrongdoing (5)
I believe the answer is:
siren
'she tempts' is the definition.
(I've seen this before)
'one again into wrongdoing' is the wordplay.
'one again' becomes 're'.
'into' means one lot of letters goes inside another.
'wrongdoing' becomes 'sin' (sin is a kind of wrongdoing).
're' inserted into 'sin' is 'SIREN'.
(Other definitions for siren that I've seen before include "Temptress - makes a loud noise!" , "Charmer" , "Attractive lady" , "'Delilah!'" , "Hooter - femme fatale" .)