L. vola = palm or sole.
L. vomer = ploughshare. The bone named vomer suggests a ploughshare by shape.
Gr. xiphos = sword, and eidos = resemblance. The name of the tip of the sternum.
Gr. xylon = wood, and polymorph = of many forms. Xylaria polymorpha is a saprobic fungus. Due to its strap-like, upright stromata it's also referred to as 'dead man's fingers'.
L. zona = a girdle, belt or zone, and the diminutive suffix -ula.
Gr. zygoma = bolt or bar, related to zygon = a yoke. Applied to the cheekbone because of its shape.