Truthful (6)
'truthful' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for candid that I've seen before include "Truthful and straightforward" , "Frank - and CID (anag)" , "Free and frank" , "Forthrightly sincere" , "Honest and open about what one thinks" .)
'truthful' is the definition.
(similar in meaning)
This is the entire clue.
(Other definitions for honest that I've seen before include "Not lying" , "Open and truthful" , "'Fair-dealing, upright (6)'" , "really!" , "Virtuous" .)