What is "xylo-"

Xylo- \Xy"lo-\ A combining form from Gr. xy`lon wood; as in xylogen, xylograph.

before vowels xyl-, word forming element meaning "wood," from comb. form of Greek xylon "wood cut and ready for use, firewood, timber; piece of wood; stocks, a plank, beam, or bench," in New Testament, "the Cross," of unknown origin.

pre. wood