decussate

The history of decussate leads us back to the intersection of decem, a word meaning "ten," and ass-, a form that refers to a unit of weight and specifically to a copper coin cut to a half-ounce. In the Roman numeral system the number 10 is represented by X, an intersection of two lines. A man named Sir Thomas Browne coined decussate in the 17th century to discuss the crossing fibers that make up human anatomy-for instance, skin tissue. The word continues to be found primarily in scientific contexts today.