What does the cryptic crossword clue "Part of satire unfair on youngster's clothing (5)" mean?

The definition is "Part of satire". The wordplay uses a hidden word. hidden in "unfair on youngster's" The answer is IRONY.

Part of satire unfair on youngster's clothing (5)

Guardian Cryptic #27556 | 13 Across | 2018-07-09 flower