Split over irregular decree that's basically worthless (3,4)
I believe the answer is:
red cent
'split' is the definition.
Both the answer and definition are singular nouns.
Maybe you can see an association between them that I don't see?
'over irregular decree that's basically worthless' is the wordplay.
I cannot quite understand how this works, but
'over' could be 're' and 're' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Another definition for red cent that I've seen is " coin".)