To deceive by sly or underhand means;

用秘密的、不正大光明的手段骗取；

A secret or underhand scheme; a plot.

阴谋，密谋秘密的或不光彩的计划；密谋。

An honest man does nothing underhand.

明人不做暗事。

To deceive by sly or underhand means; cheat.

用秘密的、不正大光明的手段骗取; 欺骗.

An honest man doesn't do anything underhand.

诚实的人不做偷偷摸摸的事情。

He got the money in a very underhand manner.

他用极为狡诈的手段弄到了这笔钱.

He used underhand methods to get himself elected.

他使用卑鄙的方法使自己得以当选。

I don't believe in getting what by underhand method.

我认为以不光明的手法获取想要得到的东西是不应该的。

To attack, damage, or destroy by underhand means; subvert.

颠覆，暗中破坏通过隐蔽的手断进攻、损害或推毁；颠覆。

But in softball, the pitcher must throw the ball underhand.

但垒球的投手必须使用下手投法.