Solely (4)
'solely' is the definition.
(I know that solely can be written as only)
This is the entire clue.
(Other definitions for only that I've seen before include "Merely; single" , "Solely, lone" , "And nothing more; sole" , "Simply" , ". . . . the Lonely (sung by Roy Orbison)" .)
'solely' is the definition.
(thesaurus)
This is the entire clue.
(Other definitions for merely that I've seen before include "'Only, and nothing more (6)'" , "Just one" , "Simply - only" .)