Chowder tidbit (4)
I believe the answer is:
clam
'chowder tidbit' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for clam that I've seen before include "Tightly closed shellfish" , "What could grip" , "Mollusc, one proverbially reticent" , "Aquatic creature" , "One is as uncommunicative as a mollusc" .)