white feather

white-feather的词性：
n.（名词）

1. A sign of cowardice.
胆怯、懦弱的迹象

2. To act like a coward.
象个胆小鬼一样行动

white-feather的词源：

3. [From the belief that a gamecock with a white feather in its tail was a poor fighter]
[从如下的观点而来：尾部带有白羽毛的斗鸡是不善斗的，没什么战斗力的劣种鸡]