Blunt or frank (6)
I believe the answer is:
candid
This clue is a double definition.
'blunt' is the first definition.
(I know that blunt can be written as candid)
'frank' is the second definition.
(I know that frank can be written as candid)
(Other definitions for candid that I've seen before include "Truthful and straightforward" , "Plain" , "Frank - and CID (anag)" , "Truthful, frank" , "Frank - open" .)