What does the cryptic crossword clue "No puritan, involving fellow in theft (8)" mean?

The wordplay uses a container (one word inside another). DON (synonym="‘fellow’") in HEIST (synonym="‘theft’") = HEDONIST The answer is HEDONIST.

No puritan, involving fellow in theft (8)

Guardian Cryptic #29424 | 8 Down | 2024-07-02 flower