What does the cryptic crossword clue "Some coped terribly and go off? (9)" mean?

The definition is "go off?". The wordplay uses an anagram. anagram of SOME + COPED = DECOMPOSE; definition: "go off?" The answer is DECOMPOSE.

Some coped terribly and go off? (9)

Daily Mail Cryptic #17124 | 7 Down | 2023-06-21 flower