What does the cryptic crossword clue "People in charge of boats keep out birds almost entirely (7)" mean?

The wordplay uses a charade (building blocks). BAR (synonym="keep out") + GEES (synonym="keep out") = BARGEES The answer is BARGEES.

People in charge of boats keep out birds almost entirely (7)

Guardian Cryptic #29720 | 28 Across | 2025-06-13 flower