Broad's all gob, possibly (6)
I believe the answer is:
global
'broad's' is the definition.
('global' can be a synonym of 'broad')
'all gob possibly' is the wordplay.
'possibly' indicates an anagram.
'all'+'gob'='allgob'
'allgob' is an anagram of 'GLOBAL'.
(Other definitions for global that I've seen before include "Of the whole world, worldwide" , "Relating to the whole world" , "Shaped like a sphere or ball" , "Across our planet" , "Across the world" .)