What does the cryptic crossword clue "Girl enters bank in a careless manner (8)" mean?

The wordplay uses a container (one word inside another). MISS (synonym="‘girl’") in RELY (synonym="‘bank’, verb") = REMISSLY The answer is REMISSLY.

Girl enters bank in a careless manner (8)

Guardian Cryptic #29558 | 5 Down | 2024-12-05 flower