Athenians for example denied their capital stinks (5)
I believe the answer is:
reeks
'stinks' is the definition.
('reek' can be a synonym of 'stink')
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for reeks that I've seen before include "offensive odours" , "Smells like the Kerry mountains." , "Smells bad" , "Macgillycuddy's - -" , "Is humming" .)