What does the cryptic crossword clue "Curdled milk, note, returned (6)" mean?

The definition is "Curdled milk". The wordplay uses a reversal. reverse of TENNER = RENNET; definition: "Curdled milk," The answer is RENNET.

Curdled milk, note, returned (6)

Times Cryptic #28827 | 28 Across | 2024-01-31 flower