X

For other uses, see X (disambiguation). The letter X is the twenty-fourth letter in the Latin alphabet. Its name in English is ex (/ɛks/). In phonetics, x is the IPA and X-SAMPA symbol for the voiceless velar fricative (IPA is used for pronunciation throughout this article). History The consonant cluster /ks/ was, in Ancient Greek, written as either Chi Χ (Western Greek) or Xi Ξ (Eastern Greek). In the end, Chi was standardized as /kʰ/ (/x/ in Modern Greek), while Xi was stan ...