One preferring solitude on tricky clues (7)
I believe the answer is:
recluse
'one preferring solitude' is the definition.
(I've seen this before)
'on tricky clues' is the wordplay.
'on' becomes 're' (regarding).
'tricky' indicates an anagram.
'clues' anagrammed gives 'cluse'.
're'+'cluse'='RECLUSE'
(Other definitions for recluse that I've seen before include "One who avoids people, like hermit" , "one stays away from people" , "One who lives alone avoiding people" , "Hermit, loner" , "Solitary person who avoids others" .)