Alone, single (8)
I believe the answer is:
solitary
This clue is a double definition.
'alone' is the first definition.
(I know that alone can be written as solitary)
'single' is the second definition.
(synonyms)
(Other definitions for solitary that I've seen before include "Lone; isolated" , "Recluse" , "Done alone" , "reclusive" , "Being the only one" .)