What does the cryptic crossword clue "As locks may be loose, bog's secured (6)" mean?

The wordplay uses a container (one word inside another). LAX (synonym="loose") in FEN (synonym="bog") = FLAXEN The answer is FLAXEN.

As locks may be loose, bog's secured (6)

Guardian Cryptic #29146 | 19 Across | 2023-08-11 flower