What does the cryptic crossword clue "Dig tunnel badly, revealing some tolerance (9)" mean?

The definition is "tolerance". The wordplay uses an anagram. anagram of DIG + TUNNEL = INDULGENT; definition: "tolerance" The answer is INDULGENT.

Dig tunnel badly, revealing some tolerance (9)

Times Cryptic #28898 | 8 Down | 2024-04-23 flower