What does the cryptic crossword clue "Man with Lucy formulated slander (7)" mean?

The definition is "slander". The wordplay uses an anagram. anagram of MAN + LUCY = CALUMNY; definition: "slander" The answer is CALUMNY.

Man with Lucy formulated slander (7)

Daily Mail Cryptic #17114 | 21 Down | 2023-06-07 flower