Chowder chunk (4)
I believe the answer is:
clam
'chowder chunk' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for clam that I've seen before include "What could grip" , "Mollusc with firmly-closed shell" , "Mollusc, one proverbially reticent" , "Shellfish - secretive person" , "Tightly closed shellfish" .)