Hint a nude oaf dances well (12)
I believe the answer is:
fountainhead
'well' is the definition.
(I know that well can be written as fountainhead)
'hint a nude oaf dances' is the wordplay.
'dances' indicates anagramming the letters.
'hint'+'a'+'nude'+'oaf'='hintanudeoaf'
'hintanudeoaf' with letters rearranged gives 'FOUNTAINHEAD'.
(Other definitions for fountainhead that I've seen before include "spring" , "Chief source" , "Original source" .)