Even in regret, the tax people still collect it (7)
I believe the answer is:
revenue
'tax people still collect it' is the definition.
I can't judge whether this definition defines the answer.
'even in regret' is the wordplay.
'in' indicates putting letters inside.
'regret' becomes 'rue' (to rue something is to regret it).
'even' inserted within 'rue' is 'REVENUE'.
'the' is the link.
Can you help me to learn more?
(Other definitions for revenue that I've seen before include "Earnings" , "profit" , "stream, perhaps" , "Gross business income" , "Ready" .)