Puppy beginning to walk further (5)
I believe the answer is:
whelp
'puppy' is the definition.
(thesaurus)
'beginning to walk further' is the wordplay.
'beginning to' indicates taking the first letters.
'further' becomes 'help'.
The first letter of 'walk' is 'w'.
'w'+'help'='WHELP'
(Other definitions for whelp that I've seen before include "Young mammal" , "Produce issue" , "Puppy, cub" , "youngster" , "Cur" .)