noun · a preface, foreword, introduction, or preamble to a piece of writing or a speech

他在新书的前言中介绍了创作的背景。

noun · words or teachings of ancient thinkers and sages

君子当多识前言往行，以畜其德。

noun · remarks, statements, or words spoken previously

他现在的这番话与前言完全不符。