The second inversion of a triad has the original top note at the bottom.

三和弦第二转位是将原最上面的音置于底部。

youdao

The first inversion of a triad has the original third at the bottom.

三和弦第一转位是将原第三音置于底部。

youdao

We're not going to get into that 'cause that takes us into heavy-duty music theory, but it's--if we don't have root position then we've got some other note of the triad in the bass, and we've got some kind of chord inversion, so that's what that particular term means up there.

我们就不深究这个问题了，这是一个冗长的音乐理论，但是如果没有了原位，三和弦的低音被另一个音所替代，这就是一种和弦转位，这就是这个词在这里的意思。

耶鲁公开课 - 聆听音乐课程节选