Support for young animal (4,2)
I believe the answer is:
prop up
'support' is the definition.
(propping up is a kind of supporting)
'for young animal' is the wordplay.
'for' becomes 'pro' (I've seen this before).
'young animal' becomes 'pup' (I've seen this before).
'pro'+'pup'='PROP UP'
(Other definitions for prop up that I've seen before include "Support" , "Keep going" , "Give financial backing" , "Underpin" .)