It's natural possibly to eat at the pub (6)
I believe the answer is:
innate
'it's natural' is the definition.
(similar in meaning)
'to eat at the pub' is the wordplay.
'to eat' becomes 'ate' (I can't explain this - if you can you should believe this answer much more).
'at' means one lot of letters go next to another (I've seen this in other clues).
'the pub' becomes 'inn' (an inn is a type of pub).
'ate' put after 'inn' is 'INNATE'.
'possibly' is the link.
Can you help me to learn more?
(Other definitions for innate that I've seen before include "Inherent, natural" , "'Inborn, not learned (6)'" , "Bred in the bone, one might say" , "Born" , "Inborn in neat way" .)