Ly·on 
(līən), Mary Mason 1797-1849.
(līən), Mary Mason 1797-1849. American educator who founded (1837) Mount Holyoke College, the first American institution of higher learning for women.
Mary Lyon- XOR
- Xosa
- Xosa
- XPS
- x-radiation
- X-rated
- x-ray
- x-ray astronomy
- 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-