What does the cryptic crossword clue "Filthy place was first to be knocked into shape (6)" mean?

The wordplay uses a charade (building blocks). STY (synonym="filthy place") + LED (synonym="was first") = STYLED The answer is STYLED.

Filthy place was first to be knocked into shape (6)

Guardian Cryptic #25714 | 28 Across | 2012-08-14 flower