What does the cryptic crossword clue "Stop, say, a misguided renunciation of belief (8)" mean?

The wordplay uses an anagram. anagram of STOP, + SAY, + A = APOSTASY The answer is APOSTASY.

Stop, say, a misguided renunciation of belief (8)

Daily Mail Cryptic #17307 | 20 Across | 2024-03-05 flower