caterpillar /katˈər-pi-lər/

1. A butterfly or moth grub
2. Extended to other insect larvae
3. An unproductive consumer (archaic)
4. (Caterpillar®) a tractor or other (esp earthmoving) vehicle running on endless articulated tracks made up of a series of flat metal plates

• X-ray
• Xray
• X-ray astronomy
• X-ray crystallography
• X-ray diffraction
• X-rayed
• X-raying
• X-ray micrography
• xrays
• X-rays
• X-ray spectrum
• X-ray telescope
• X-ray therapy
• X-ray tube
• X-ray tubes
• Xt
• Xtian
• xu
• XXL
• xyl-
• xylem
• xylems
• xylene
• xylenes
• xylenol