Ｘ

noun

X; the letter X

Refers to the letter X itself, as in the alphabet, or as a symbol.

• この書しょ類るいのＸのところに署しょ名めいしてください。

  Please sign at the X on this document.

• アルファベットのＸは「エックス」と読よむ。

  The letter X in the alphabet is read as 'ekkusu'.

noun

unknown quantity; an unknown

Used in mathematics or general contexts to represent an unknown value, person, or factor.

• 方ほう程てい式しきのＸを求もとめなさい。

  Find the value of X in the equation.

• 彼かれの実じつ力りょくはまだＸだ。

  His true ability is still an unknown.