slip of the tongue

In a slip of the tongue the schemer exposed his true motivation.

阴谋者一时口误暴露了自己的动机。

The classic error of this type is the spoonerism (or slip of the tongue), where the initial letter or letters of two words are transposed.

属于这种类型的典型错误是音互换（或叫“舌头打滑”）：两个单词的前个或前几个字母互换了位置。