Improvised corn deal that won't hold water (8)
I believe the answer is:
colander
'hold water' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe you can see an association between them that I can't see?
'improvised corn deal that won't' is the wordplay.
'corn deal' anagrams to 'COLANDER'.
But, I am unsure how this is indicated.
Can you help me to learn more?
(Other definitions for colander that I've seen before include "Bowl-shaped strainer" , "kitchen utensil" , "Food strainer" , "implement that's full of holes" , "Old crane (anag.)" .)