Separate secret I'd unravelled (8)
I believe the answer is:
discrete
'separate' is the definition.
('discrete' can be similar in meaning to 'separate')
'secret i'd unravelled' is the wordplay.
'unravelled' is an anagram indicator.
'secret'+'id'='secretid'
'secretid' is an anagram of 'DISCRETE'.
(Other definitions for discrete that I've seen before include "Individually distinct in discreet way" , "Individually self-contained in discreet way" , "Individually separate and distinct" , "Individually distinct, discontinuous" , "independent" .)