According to my Oxford American Desk Dictionary & Thesaurus, X is for things like:
I won a prize at our ground water convention by knowing the definition of xylem. I didn’t really know. I looked it up and memorized it. It didn’t matter. That’s the way anyone else who won did it. It was just a fun contest to get people to that particular vendor’s booth. What did I win? I don’t even know. Some kind of small pump that I’m sure Jim could find a use for it though.
For your information xylem means (according to my dictionary): woody tissue. It’s really more than that though it’s the woody supportive plant tissue that carries water and dissolved minerals from the roots through the stem and leaves. And that’s significant to the name of that particular company who was giving away the prizes.
Aren’t you glad I didn’t pick xanthophyll as my X-word again? 🙂