Block and close tab that’s dodgy (8)
I believe the answer is:
'block' is the definition.
(I've seen this before)
'close tab that's dodgy' is the wordplay.
'that's dodgy' is an anagram indicator.
'closetab' with letters rearranged gives 'OBSTACLE'.
'and' is the link.
(Other definitions for obstacle that I've seen before include "Progress blocker" , "Barrier or deterrent" , "Blockage, hindrance" , "Thing blocking progress" , "Stab Cleo (anag) - which hinders progress" .)