Write in hope, naturally (3)
I believe the answer is:
pen
'write' is the definition.
(synonyms)
'in hope naturally' is the wordplay.
'in' indicates a hidden word.
'PEN' is hidden within 'hope naturally'.
(Other definitions for pen that I've seen before include "record" , "Writing tool" , "Coop" , "Animal enclosure" , "'The ... is mightier than the sword'" .)