reef
n part of the top or bottom of a sail that can be rolled or folded to reduce the area exposed to the wind 缩帆部, 叠帆部(帆的顶部或底部可卷起或摺起的部分). reef, v [Tn]
reduce the area of (a sail) by drawing in a reef or reefs 卷起或摺起(缩帆部).
reef n ridge of rock, shingle, sand, etc at or near the surface of the sea 礁; 礁脉
The ship was wrecked on a coral reef. 那艘船触珊瑚礁失事.