What does the cryptic crossword clue "Comb a cat found in vault (8)" mean?

The definition is "vault". The wordplay uses an anagram. anagram of COMB + A + CAT = CATACOMB; definition: "vault" The answer is CATACOMB.

Comb a cat found in vault (8)

Guardian Cryptic #24406 | 4 Down | 2008-06-04 flower