Go to and fro out West, say (4)
I believe the answer is:
sway
'go to and fro' is the definition.
The answer and definition can be both acts as well as being singular nouns.
Perhaps you can see an association between them that I don't see?
'out west say' is the wordplay.
'out' indicates an anagram.
'west' becomes 'w' (synonyms).
'w'+'say'='wsay'
'wsay' with letters rearranged gives 'SWAY'.
Can you help me to learn more?
(Other definitions for sway that I've seen before include "Influence; dominance" , "Bend; influence" , "Lean from side to side - influence" , "Move from side to side; influence" , "Oscillate" .)