What does the cryptic crossword clue "Removal of hard skin from undercoat and its base (12)" mean?

The wordplay uses an anagram. anagram of UNDERCOAT (synonym="UNDERCOAT") + ITS (synonym="ITS") = DECRUSTATION The answer is DECRUSTATION.

Removal of hard skin from undercoat and its base (12)

Guardian Cryptic #29361 | 10 Down | 2024-04-19 flower