Block presenting problem for observers circling road (6)
I believe the answer is:
stymie
'block' is the definition.
('stymie' can be a synonym of 'block')
'observers circling road' is the wordplay.
'observers' becomes 'stye' (I can't explain this - if you can you should believe this answer much more).
'circling' means one lot of letters goes inside another (circling can mean going around or containing).
'road' becomes 'mi'.
'stye' enclosing 'mi' is 'STYMIE'.
'presenting problem for' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for stymie that I've seen before include "Hinder the progress of (something)" , "Block or thwart, perhaps on putting green" , "Tricky situation" , "Impede, say golf stroke" , "Prevent (by getting in the way)" .)