"in Paris the subway system is called the `metro' and in London it is called the `tube' or the `underground'"
"inside Paris, they used to tube mail"
"We tubed down the river on a hot summer day"
The Mercury in the Tube fell down lower, about three inches.
He kicked aside cardboard tubes holding maps.
牛津高阶第八版
美国韦氏词典
Dictionary.com
Free Dictionary
维基百科 (自由的百科全书)