Seemingly hungry chap gives a whimper! (4)
I believe the answer is:
moan
'whimper' is the definition.
(thesaurus)
'seemingly hungry chap gives a' is the wordplay.
'seemingly hungry chap gives' becomes 'mo' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'a' becomes 'an'.
'mo'+'an'='MOAN'
Can you help me to learn more?
(Other definitions for moan that I've seen before include "Lament; grumble" , "Complain, groan" , "Bewail" , "Complain; mournful sound" , "Whinge" .)