What does the cryptic crossword clue "Glasses of wine knocked back in bad temper (5)" mean?

The definition is "temper". The wordplay uses a reversal. PORTS (reversal="glasses of wine") = STROP; definition: "bad temper" The answer is STROP.

Glasses of wine knocked back in bad temper (5)

Guardian Cryptic #29303 | 27 Across | 2024-02-12 flower