What does the cryptic crossword clue "Nonconformist mostly tucked into quantity of wine, employing a bit of brain (10)" mean?

The wordplay uses a container (one word inside another). REBE (synonym="REBE") in CELLAR (synonym="CELLAR") = CEREBELLAR The answer is CEREBELLAR.

Nonconformist mostly tucked into quantity of wine, employing a bit of brain (10)

Guardian Cryptic #29651 | 18 Across | 2025-03-25 flower