Cheating, in a huff until rehabilitated (10)
I believe the answer is:
unfaithful
'cheating' is the definition.
(similar in meaning)
'a huff until rehabilitated' is the wordplay.
'rehabilitated' indicates an anagram.
'a'+'huff'+'until'='ahuffuntil'
'ahuffuntil' with letters rearranged gives 'UNFAITHFUL'.
'in' acts as a link.
(Other definitions for unfaithful that I've seen before include "Cheating" , "Disloyal" , "like an atheist?" , "Adulterous" .)