Loner about to solve clues (7)
I believe the answer is:
recluse
'loner' is the definition.
(I know that recluse is a type of loner)
'about to solve clues' is the wordplay.
'about' becomes 're' (regarding).
'to solve' indicates an anagram (I've seen 'solved' mean this (the anagram must be solved)).
'clues' anagrammed gives 'cluse'.
're'+'cluse'='RECLUSE'
(Other definitions for recluse that I've seen before include "Solitary individual" , "What, say, Howard Hughes became" , "Person living in solitude" , "One who lives away from the world" , "One has withdrawn from society" .)