1N-VAR 黄瓜 A cucumber is a long thin vegetable with a hard green skin and wet transparent flesh. It is eaten raw in salads. 黄瓜
2PHRASE (尤指意料之外地)非常冷静,泰然自若 If you say that someone is as cool as a cucumber, you are emphasizing that they are very calm and relaxed, especially when you would not expect them to be. (尤指意料之外地)非常冷静,泰然自若 [emphasis]
You can hardly be held responsible for Darrow waltzing in, cool as a cucumber, and demanding thousands of pounds.