ninth

名词 ninth:

1. position nine in a countable series of things
2. one part in nine equal parts
   同义词：one-ninth

形容词 ninth:

1. coming next after the eighth and just before the tenth in position
   同义词：9th

1. What did the suspect do on July ninth?
   嫌疑犯在七月九日做了什么事情？
2. The body of law established by the Danish invaders and settlers in northeast England in the ninth and tenth centuries.
   丹麦法在9世纪和10世纪时，由丹麦入侵者和殖民者在英国东北部施行的法律体系
3. A chord consisting of a root with its third, seventh, and ninth.
   九和弦由第三、第七和第九三个基础音组成的和弦
4. He took the ninth position in his class of forty.
   他在40 个人的班级里排第九名。

ninth

n.（名词）
The ordinal number matching the number nine in a series.
第九：在数列中与数字9相配的序数词
One of nine equal parts.
九分之一：九等份中的一份
Music
【音乐】
A harmonic or melodic interval of an octave and a second.
九度音程：包含一个八度音程和第二度音程的合音或音程
The tone at the upper limit of such an interval.
这个音程内的最高一个音调
A chord consisting of a root with its third, seventh, and ninth.
九和弦：由第三、第七和第九三个基础音组成的和弦

来源：
Middle English ninthe
中古英语 ninthe
from Old English nigonthe
源自 古英语 nigonthe
from nigon [nine] * see newô
源自 nigon [九] *参见 newô

【引伸】
ninth
adv.（副词）
adj.（形容词）