<P> There are very few English words that start with ⟨ x ⟩ ( the fewest number of any letter ) . When ⟨ x ⟩ does start a word , it is usually pronounced / z / ( e.g. xylophone , xenophobia , and xanthan ) ; in rare recent loanwords or foreign proper names , it can also be pronounced / s / ( e.g. the obsolete Vietnamese monetary unit xu ) or / ʃ / ( e.g. Chinese names starting with Xi like Xiaomi or Xinjiang ) . Many of the words that start with ⟨ x ⟩ are of Greek origin , or standardized trademarks ( Xerox ) or acronyms ( XC ) . In abbreviations , it can represent `` trans - '' ( e.g. XMIT for transmit , XFER for transfer ) , `` cross - '' ( e.g. X-ing for crossing , XREF for cross-reference ) , `` Christ - '' as shorthand for the labarum ( e.g. Xmas for Christmas , Xian for Christian ) , the `` crys - '' in crystal ( XTAL ) , or various words starting with `` ex - '' ( e.g. XL for extra large , XOR for exclusive - or ) . </P>
when does an x sound like a z
When ⟨ x ⟩ does start a word