- [countable, uncountable]
the 24th letter of the English alphabet 英语字母表的第 24 个字母 ‘Xylophone’ begins with (an) X/‘X’. xylophone 一词以字母 x 开头。
- [uncountable] (
mathematics )数学 used to represent a number whose value is not mentioned (代表未知数) - [uncountable]
a person, a number, an influence, etc. that is not known or not named 未知的人(或数、影响等);未指明的人(或数、影响等) see also X chromosome, X-rated, X-ray