A five o'clock shadow is facial stubble. It sometimes describes a man's beard at the end of the day.

Five o'clock shadow是指胡子，就是男生一天下来，到下午五点就会长出来的一点点胡子。

A five o'clock shadow is facial stubble, it sometimes describes a man's beard at the end of the day.

原来five o'clock shadow是指胡子，就是男生一天下来，到下午五点就会长出来的一点点胡子, 所以人们就用five o'clock shadow来形容男生脸上的胡子茬子。