Puppy beginning to walk requiring assistance (5)
I believe the answer is:
whelp
'puppy' is the definition.
(I've seen this before)
'beginning to walk requiring assistance' is the wordplay.
'beginning to' indicates taking the first letters.
'requiring' says to put letters next to each other.
'assistance' becomes 'help' (synonyms).
The first letter of 'walk' is 'w'.
'w'+'help'='WHELP'
(Other definitions for whelp that I've seen before include "youngster" , "Offspring of wolf" , "bear" , "Have puppies" , "Puppy- young wolf" .)