Each walkway goes in one direction only (4)
I believe the answer is:
east
'only' is the definition.
Both the definition and answer are adjectives. Maybe they are linked in a way I don't understand?
'each walkway goes in one direction' is the wordplay.
I cannot quite see how this works, but
'each' could be 'ea' (abbreviation) and 'ea' is located in the answer.
'direction' could be 's' (S is an example) and 's' is found in the answer.
A single letter 't' remains which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for east that I've seen before include "Direction taken when going from the US towards Ireland" , "To right if facing North" , "Ninety degree bearing" , "Asia" , "Bearing of 90 degrees" .)