This is the 273rd most frequent Chinese word.
第三
"第三" means "third."
The word "第三" is used as an ordinal number, indicating the position in a sequence (the third instance).
这是我第三次来这家餐厅。
This is my third visit to this restaurant.
Here, "第三" denotes a ranking position in a competitive setting.
在比赛中，他跑到了第三名。
In the competition, he finished in third place.
In this context, "第三" is used to specify the position of a chapter within a book.