What does the cryptic crossword clue "Hill backing Red Bull’s sporting rivals? (7)" mean?

The wordplay uses a charade (building blocks). TOR (synonym="“hill”") + SORE (reversal="“red”") = TOREROS The answer is TOREROS.

Hill backing Red Bull’s sporting rivals? (7)

Guardian Cryptic #29508 | 13 Across | 2024-10-08 flower