名詞 reef:

1. a submerged ridge of rock or coral near the surface of the water
2. a rocky region in the southern Transvaal in northeastern South Africa; contains rich gold deposits and coal and manganese
   同義詞：Witwatersrand, Rand

動詞 reef:

1. lower and bring partially inboard
2. roll up (a portion of a sail) in order to reduce its area
3. reduce (a sail) by taking in a reef

1. The ship struck a hidden reef and went dawn with all hands.
   船只撞上暗礁與全體船員一起沉沒。
2. Our ship was able to haul up just before it hit the submerged reef.
   我們的船就在要撞上暗礁的時候停住了。
3. The ship was wrecked on a reef.
   這船觸礁失事了。

reef

n.Abbr. rf.（名詞）縮寫 rf.
A strip or ridge of rocks, sand, or coral that rises to or near the surface of a body of water.
礁，暗礁：上升到水面或接近水面的條狀或脊?fàn)顜r石、泥沙或珊瑚
A vein of ore.
礦脈

來源：
Obsolete Dutch rif
已廢荷蘭語 rif
possibly from Old Norse [ridge]
可能源自 古斯堪的納維亞語 [脊]

【引伸】
reef.y
adj.（形容詞）

---------------另--------------
reef
reef 2

n.（名詞）
A portion of a sail rolled and tied down to lessen the area exposed to the wind.
縮帆部：帆的一部分，卷起并落下捆住以減少受風(fēng)面積
v.tr.（及物動詞）
reefed,reef.ing,reefs
To reduce the size of (a sail) by tucking in a part and tying it to or rolling it around a yard.
縮帆：把（帆）收回一部分并系上或在甲板上卷上以減小其面積
To shorten (a topmast or bowsprit) by taking part of it in.
縮桅：通過收回一部分的方法來縮短（中桅或船首斜桁）

來源：
Middle English riff
中古英語 riff
from Old Norse rif [ridge, reef]
源自 古斯堪的納維亞語 rif [脊，縮帆部]