X-Reference
An external drawing attached to another drawing, which is read transparently without altering its contents.
Xypex
Xypex is a non-toxic, chemical treatment & additive for the waterproofing, durability enhancement, repair and protection of concrete from a range of aggressive mediums.
Xystus
1. Tree-lined walk
2. A Greek architectural term for the covered portico of the gymnasium, in which the exercises took place during the winter or in rainy weather, etc.
3. A Roman term for a garden walk in front of the porticoes, which was divided into flower beds with borders of box, and to a promenade between rows of large trees.