Xy

Xylene
An aromatic hydrocarbon derived from petroleum and used to increase octane.

Xylitol

C5H12O5

Naturally found in low concentrations in the fibers of many fruits and vegetables, and can be extracted from various berries, oats, and mushrooms, as well as fibrous material such as corn husks and sugar cane bagasse and birch.

Xylol
A commercial preparation of xylenes (alternatively known as dimethylbenzenes).