ninth

1. ORD The ninth item in a series is the one that you count as number nine. 第9

...January the ninth. …1月9号。

...students in the ninth grade. …9年级的学生们。

2. FRACTION Aninth is one of nine equal parts of something. 1/9

The dollar rose by a ninth of a cent. 美元升值了1/9美分。