What does the cryptic crossword clue "Puts waterproof coat on — so Cleopatra survives a little longer? (8)" mean?

The definition is "Puts waterproof coat on". The wordplay uses a cryptic definition. Cryptic definition The answer is ASPHALTS.

Puts waterproof coat on — so Cleopatra survives a little longer? (8)

Times Cryptic #28641 | 1 Across | 2023-06-28 flower