In Xanadu did Kubla Khan A stately pleasure-dome decree:
Perhaps because the KS sound makes a perfectly good substitute, the letter X remains the most underutilized letter in the entire alphabet -- appearing in a less than 3% of all English words. So when we see the letter X in a word, it tends to stand out and force us to take notice.
But on the heels of the Generation-X, the X has recently experienced a surge in popularity. Microsoft named its video-game system the Xbox, Christine Aguilera has taken to calling herself Xtina, Nissan named their top selling SUV the Xterra, and the X-games are one of the most-watched sporting events on Fox. Along with the huge commercial successes of the films X-men and X-men, the names Xander (short for Alexander) and Xavier appeared on the list of the top one hundred baby names issued by the Social Security Administration in 2002. The name Xena is also rapidly growing in popularity due to the success of the television character made famous by Lucy Lawless.
The X the classic unknown value in algebra and its isolated disposition is well illustrated by the word xenophobia. When Wilhelm Roentgen discovered mysterious rays emanating from a piece of radioactive uranium, he named them X-rays in deference to the letter’s elusive properties. The X also marks the spot and is the name given to anything wishing to remain anonymous, as in: Brand X, Mr. X, and the X-Files. Movies you don’t want your kids to see are labeled XXX, in the same way as beer is labeled in comic books.
Still, there are fewer people in the United States whose names begin with an X than any other letter (less than 1/100 of a percent), so it’s clear that parents who give their child an X name are making a strong statement about the uniqueness of their offspring.