Meaning of X in English
X, the twenty-fourth letter of the English alphabet, has three sounds; a compound nonvocal sound (that of ks), as in wax; a compound vocal sound (that of gz), as in example; and, at the beginning of a word, a simple vocal sound (that of z), as in xanthic.
Webster's Revised Unabridged English Dictionary. Пересмотренный полный словарь английского языка Webster. 2012