What does the cryptic crossword clue "Sound demeanour for one who'll succeed (4)" mean?

The definition is "one who’ll succeed". The wordplay uses a homophone (sounds like). Sounds like “air” (demeanour) The answer is HEIR.

Sound demeanour for one who'll succeed (4)

Times Cryptic #28760 | 18 Across | 2023-11-14 flower