What does the cryptic crossword clue "Untidy heap surrounds trench at graveyard it's observed (7)" mean?

The wordplay uses a container (one word inside another). anagram of PIT (synonym="PIT") + HEAP (synonym="HEAP") = EPITAPH The answer is EPITAPH.

Untidy heap surrounds trench at graveyard it's observed (7)

Independent Cryptic #11866 | 22 Down | 2024-10-21 flower