Exclusively (4)
'exclusively' is the definition.
(I know that exclusively can be written as only)
This is all the clue.
(Other definitions for only that I've seen before include "Alone; solitary" , "And no one else" , "Exclusive - individual" , "Existing alone with no other, perhaps a child" , "Simply" .)
'exclusively' is the definition.
(I know that exclusively can be written as solely)
This is the entire clue.
(Other definitions for solely that I've seen before include "alone" , "nowhere else?" , "Singly" , "Singularly" , "Exclusively, only" .)