What does the cryptic crossword clue "Two gulls and another bird (9)" mean?

The wordplay uses a charade (building blocks). SAP (synonym="SAP") + SUCKER (synonym="SUCKER") = SAPSUCKER The answer is SAPSUCKER.

Two gulls and another bird (9)

Guardian Cryptic #29383 | 17 Across | 2024-05-15 flower