X contact X接點（萬次及MF級燈閃光連動用）
X-ary diffraction topography X射線衍射拓捕學
X-axis X軸[線]
X-band X帶
X-component X軸向分量
X-coordinate X坐標，橫坐標
X-cut crystal X切割晶體
X-flash  X閃光燈
X-line X軸，X線
X-parallax X視差
X-radiation X輻射
X-radioray X射線
X-ray (Rontgen ray) X射線（倫琴射線）
X-ray crystal analysis X射線結晶分析
X-ray crystallography X射線晶體學
X-ray detectoscopy X射線探傷法
X-ray diffraction X射線衍射
X-ray diffraction camera X射線衍射照相機
X-ray diffraction contrast X射線衍襯法
X-ray diffractogram X射線衍射圖
X-ray diffractometer X射線衍射儀
X-ray diffractometry X射線衍射測量術
X-ray emission spectrum X射線發射譜
X-ray examination X射線檢查
X-ray fluorescence X射線熒光
X-ray hologram X射線全息圖
X-ray holography X射線全息術
X-ray image dissection X射線析像
X-ray image intensifier X線像加強器
X-ray imaging telescope X射線望遠鏡
X-ray inspection X射線檢查
X-ray interferometer X射線干涉儀
X-ray interferometry X射線干涉測量術
X-ray laser X射線激光器
X-ray metallography X射線金相學
X-ray microbeam technique X射線微束技術
X-ray microscope X射線顯微鏡
X-ray microscopy X射線顯微術
X-ray monochromator X射線單色器
X-ray optics X射線光學
X-ray photograph X射線照相
X-ray photography X光照相術
X-ray radiography X射線照相
X-ray space detector X射線宇宙探測器
X-ray spectrograph X射線攝譜儀
X-ray spectrography X射線攝譜學
X-ray spectrometer X射線分光計
X-ray telespcope X射線望遠鏡
X-ray transmission photograph X射線透射照相
X-ray-induced fluorescence X射線感應發光，X射線感應熒光
X-tal 晶體
X-tilt X傾角
X-tube X[形]管
X-type X形，交叉形
X-unit(X.U.) X單位（波長單位，=10-11厘米）
xanhopsia 黃視癥
xaser (X-ray laser) X射線激光器
Xe-lamp 氙燈
XeF laser 氟化氙激光器
xenon  (Xe)氙
Xenon /Xenon Flashlamps Light Sources 氙燈
xenon excimer laser 氙受激準分子激光器
xenon flash lamp 氙閃光燈
xenon flashtube 氙-氦激光器
xenon lamp 氙燈
xenon laser 氙激光器
Xenon Lasers 氙分子雷射
xenon long-arc lamp 長弧氙燈
xenon pulsed light source 脈沖氙燈
xenon search light 氙控照燈
xenon short-arc lamp 短弧氙燈
xenon tube 氙燈
xenon-acr lamp 氙弧燈
xenon-filled flashtube 充氙閃光管
xenon-filled linear flash lamp 充氙線性閃光燈
xenon-helium laser 氙-氪激光器
xenon-mercury lamp 汞氙燈
xerography 靜電印刷術，乾印術
xeroradiography 干板X射線照相術
xerox 靜電印刷復制
xi-jhyperon X超子
xylene 二甲苯
xyloid 木質的
xylol 混合二甲苯
xylonite 賽珞璐（熱塑性硝化纖雄）