What does the cryptic crossword clue "Denying tiger fun proves foolish (8)" mean?

The definition is "Denying". The wordplay uses an anagram. anagram of TIGER + FUN = REFUTING; definition: "Denying" The answer is Refuting.

Denying tiger fun proves foolish (8)

Telegraph Prize Cryptic #3035 | 21 Across | 2019-12-22 flower