Accessible; frank (4)
I believe the answer is:
open
I believe this is a double definition.
'accessible' is the first definition.
(something open can be accessed)
'frank' is the second definition.
(synonyms)
(Other definitions for open that I've seen before include "Accessible - candid" , "Not closed or obstructed" , "Undo; ajar" , "Traditional room heater" , "gaping" .)