Repeat for each hoof, regularly (4)
I believe the answer is:
echo
'repeat' is the definition.
(I know that repeat can be written as echo)
'each hoof regularly' is the wordplay.
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
'each'+'hoof'='eachhoof'
The alternate letters of 'eachhoof' are 'ECHO'.
'for' acts as a link.
(Other definitions for echo that I've seen before include "Reflection of sound waves" , "Languishing nymph" , "Before foxtrot" , "Parrot" , "repercussion" .)