Pets returning from a walk (4)
I believe the answer is:
step
'a walk' is the definition.
(I know that step is a kind of the walk)
'pets returning' is the wordplay.
'returning' says the letters should be written in reverse.
'pets' reversed gives 'STEP'.
'from' is the link.
(Other definitions for step that I've seen before include "A pace for pets" , "Tread - stage" , "Move a little way" , "short distance" , "Football" .)