Is able to be a bit buccaneering (3)
I believe the answer is:
can
'is able to' is the definition.
(if you can do something you are able to do it)
'a bit buccaneering' is the wordplay.
'a bit' says the answer is hidden in the clue (the answer is formed by a bit of the clue).
'CAN' can be found hidden inside 'buccaneering'.
'be' acts as a link.
(Other definitions for can that I've seen before include "Vessel" , "John" , "(Tin) container" , "Cooler" , "let go in the US" .)