Can such a profit be fishy? (3)

I believe the answer is:

net

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'can' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps they are linked in a way I don't understand?

I don't understand how the rest of the clue works.

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(Other definitions for net that I've seen before include "Mesh; profit" , "difficulty" , "Fine open-weave fabric" , "Clear profit or gain" , "Mesh; entrap" .)

I've seen this clue in the Evening Standard.

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