Look for a sign that a chick has hatched (4)
I believe the answer is:
peep
'look' is the definition.
(peep can mean to look at something)
'sign that a chick has hatched' is the wordplay.
I cannot really see how this works, but
'sign' could be 'pe' (pe is a kind of sign) and 'pe' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
'for a' is the link.
Can you help me to learn more?
(Other definitions for peep that I've seen before include "Look furtively or voyeuristically" , "Look furtively (either way)" , "Spy" , "Palindromic glimpse" , "Furtive look" .)