xerography
xerography: n. a dry copying process in which black or coloured powder adheres to parts of a surface remaining electrically charged after exposure of the surface to light from an image of the document to be copied. xerographic adj. xerographically adv.

xylophone
xylophone: n. a musical instrument of wooden or metal bars graduated in length and struck with a small wooden hammer or hammers. xylophonic adj. xylophonist n. [Gk xulon wood + -PHONE]

xanthoma
xanthoma: n. (pl. xanthomas or xanthomata) Med.
1 a skin disease characterized by irregular yellow patches.
2 such a patch. [as XANTHIC + -OMA]