the 24th letter of the English alphabet
Example:
- ‘Xylophone’ begins with (an) X/‘X’.
used to represent a number whose value is not mentioned
Example:
- The equation is impossible for any value of x greater than 2.
a person, a number, an influence, etc. that is not known or not named
Example:
- Let's suppose X knows what Y is doing.
a social media service (previously called Twitter™) that allows you to send out short messages about what you are doing or thinking that people can access on the internet or on their mobile phones