What does the cryptic crossword clue "Role spy played in infectious disease (7)" mean?

The definition is "disease". The wordplay uses an anagram. anagram of ROLE + SPY = LEPROSY; definition: "disease" The answer is LEPROSY.

Role spy played in infectious disease (7)

Daily Mail Cryptic #17499 | 10 Across | 2024-11-28 flower