I'd backed secret reforms, being detached (8)
I believe the answer is:
discrete
'being detached' is the definition.
(thesaurus)
'i'd backed secret reforms' is the wordplay.
'i'd' becomes 'id' (**).
'backed' says the letters should be written backwards.
'reforms' indicates an anagram.
'id' in reverse letter order is 'di'.
'secret' anagrammed gives 'screte'.
'di'+'screte'='DISCRETE'
(Other definitions for discrete that I've seen before include "Individual" , "Unattached" , "Individually self-contained in discreet way" , "independent" , "Individually distinct, discontinuous" .)