The Dutch word that immediately comes into mind is the xylofoon. It sounds similar to the English xylophone. On the internet I found this French stamp, showing one:

The neXt words are similar in Dutch and many other languages:
On the internet I searched for stamps about the historical figure Xerxes (I or II). But the only one directly showing 'xerxes' was this stamp of this ant whose second name is xerxes:

Years ago I saw a nice movie (one of my favourites), located in the south of Africa, whose main character was named Xi. I thought them to speak Xhosa, but I was wrong, though the language might have some similarities (I should study on that to be sure). Despite of this, 'Xhosa', both language and people, of course offer a new chance to find stamps. And I found stamps dedicated to the Xhosa people, among them this one:

See what other stamps related to the letter 'x' mail lovers have found on and via today's Sunday Stamps!
I hope you will get these interesting stamps one day!
BeantwoordenVerwijderenInsect names are an excellent resource for the letter X although ants do look rather creepy at that scale. Love those Zhosa dances, a fascinating language to hear with its clicks.
BeantwoordenVerwijderensome nice finds, and nice to see another scientific name crop up.
BeantwoordenVerwijderenThe Gods Must Be Crazy! Also a favourite movie of mine :)
BeantwoordenVerwijderenFine stamps for 'X'
BeantwoordenVerwijderennot one but three 'x' stamps, excellent finds!
BeantwoordenVerwijderen