What does the cryptic crossword clue "Sign-off that might end with an ‘x’? (5)" mean?

The definition is "Sign-off that might end with an ‘x’?". The wordplay uses a cryptic definition. Cryptic definition The answer is ADIEU.

Sign-off that might end with an ‘x’? (5)

Guardian Cryptic #29611 | 24 Down | 2025-02-06 flower