Wetland walk out of bounds for shepherd (7)
I believe the answer is:
marshal
'for shepherd' is the definition.
(both can mean to gather)
'wetland walk out of bounds' is the wordplay.
'wetland' becomes 'marsh' (I've seen this in another clue).
'out of bounds' means to look at the middle letters (the bounds or edges of the word are removed).
The centre of 'walk' is 'al'.
'marsh'+'al'='MARSHAL'
(Other definitions for marshal that I've seen before include "assemble together" , "Shepherd" , "Law officer in the old Wild West" , "Arrange in order" , "Assemble and arrange" .)