Fashionable top female to rave, never able to be wrong (8)
I believe the answer is:
inerrant
'never able to be wrong' is the definition.
'fashionable top female to rave' is the wordplay.
'fashionable' becomes 'in' ('in' can be similar in meaning to 'fashionable').
'top' means to remove the first letter.
'female' becomes 'her' (I've seen this before).
'to rave' becomes 'rant' ('rant' can be a synonym of 'rave').
'her' with its initial letter taken away is 'er'.
'in'+'er'+'rant'='INERRANT'
(Other definitions for inerrant that I've seen before include "Just like Pope" , "Infallible; art inner (anag.)" , "right all the time?" , "without fail" .)