Turn round after extremely short walk (6)
I believe the answer is:
stroll
'turn' is the definition.
(thesaurus)
'after extremely short walk' is the wordplay.
'after' means one lot of letters go next to another.
'extremely' says to hollow out the word (remove centre letters) (only the extremes of the word are used).
'walk' becomes 'roll' (roll is a kind of walk).
'short' with its centre removed is 'st'.
'st' put next to 'roll' is 'STROLL'.
'round' is the link.
(Other definitions for stroll that I've seen before include "walk in a leisurely manner" , "A casual or leisurely walk" , "Saunter in no particular direction" , "cinch" , "gentle pace" .)