Fishy, perhaps, it's simply full of holes! (3)
I believe the answer is:
'fishy' is the definition.
Both the definition and answer are adjectives. Perhaps they are linked in a way I don't understand?
'it's simply full of holes' 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 understand.
This may be the basis of the clue (or it may be nonsense).
'perhaps' acts as a link.
Can you help me to learn more?
(Other definitions for net that I've seen before include "Fish-catcher" , "Cricket practice area" , "land" , "catch fish" , "Mesh for the bottom line?" .)