What does the cryptic crossword clue "With another club, possibly, beat uncovered backside (9)" mean?

The wordplay uses a charade (building blocks). OVERT (synonym="OVERT") + RUMP (synonym="RUMP") = OVERTRUMP The answer is OVERTRUMP.

With another club, possibly, beat uncovered backside (9)

Guardian Cryptic #29403 | 29 Across | 2024-06-07 flower