Full of holes, it doesn't really hold water (3)
I believe the answer is:
net
'hold water' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Perhaps you can see an association between them that I can't see?
'full of holes it doesn't really' is the wordplay.
I cannot quite understand how this works, but
'it' could be 't' (abbreviation. e.g. in 'tis) and 't' is present in the answer.
The remaining letters 'ne' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for net that I've seen before include "Meshwork" , "Make" , "Open-meshed material (used for catching things?)" , "Ultimate" , "Open weave fabric" .)