Obvious it's unblocked (5)
I believe the answer is:
clear
I believe this clue is a double definition.
'obvious' is the first definition.
('clear' can be similar in meaning to 'obvious')
'unblocked' is the second definition.
(thesaurus)
'it's' acts as a link.
(Other definitions for clear that I've seen before include "Obvious; jump over" , "Evident" , "Set free of charges" , "Plainly" , "Unimpeded" .)