What does the cryptic crossword clue "Rock cover generates complaint for Young Ones (6,3)" mean?

The wordplay uses a charade (building blocks). CRADLE (synonym="Rock") + CAP (synonym="cover") = CRADLECAP The answer is CRADLECAP.

Rock cover generates complaint for Young Ones (6,3)

Guardian Cryptic #29390 | 12 Across | 2024-05-23 flower