path·break·er 
(păthbrā′kər, päth-)
(păthbrā′kər, päth-)n.
1. One that opens a path or trail.
2. One that is original or innovative; a pioneer.
- x-ray burster
- x-ray crystallography
- x-ray diffraction
- x-ray fish
- x-ray microscope
- x-ray photoemission spectroscopy
- x-ray spectrometer
- x-ray spectrometry
- x-ray spectroscope
- x-ray spectroscopy
- x-ray star
- x-ray therapy
- x-ray tube
- Xuthus
- Xuzhou
- xyl-
- xyl-
- xylan
- xylem
- xylene
- xylidine
- xylitol
- xylo-
- Xylocaine
- xylograph