There are things called DICTIONARIES. If you are on your computer, you can access one at http://reference.dictionary.com Dictionaries are organized by LETTER. Is that sufficient? By looking in a dictionary, you can find: xi, xenophobia, xylophone, xenon, xeric, xed, x-ray, xu, xylem, etc...
Xenophilia is a friendly word. It describes a person who is attracted to that which is foreign.
X-Cell, X-Dial, X-ray.These are some words that start with X.Hope this answers your question.
x-ray
X-Rays
There are words that start with every letter of the alphabet in mathematics. For x some words are x-intercept, x-y plane, x-z plane, and Xi.
xces-x
x axsis
X-Ray, Xerox
Xlen
· x-rated · xenophobic
x and y axis
Xenophobic
Xenia