Accessible (2,4)
'accessible' is the definition.
(something open can be accessed)
This is the entire clue.
(Other definitions for open that I've seen before include "Unrestricted; ready for business" , "Frank; unfold" , "Release" , "Overt" , "Golf tournament" .)
'accessible' is the definition.
(thesaurus)
This is all the clue.
(Another definition for to hand that I've seen is " Nearby".)