This is the 797th most frequent Chinese word.
第四
"第四" means "fourth."
Ordinal number used to specify the sequence of chapters in a book or text.
第四章讲的是概率论的基本定义。
The fourth chapter discusses the basic definitions of probability theory.
Ordinal number indicating a rank or positioning in a competitive setting.
比赛结果显示，我获得了第四名。
The competition results showed that I achieved the fourth place.
Ordinal number indicating the sequence of days within a specified period.