What does the cryptic crossword clue "Stubborn stain to be disguised (9)" mean?

The definition is "Stubborn". The wordplay uses an anagram. anagram of STAIN + TO + BE = OBSTINATE; definition: "Stubborn" The answer is OBSTINATE.

Stubborn stain to be disguised (9)

Independent Cryptic #11970 | 27 Across | 2025-02-19 flower