X-rays 4,249 Xenophobia 1,627 X-ray spectroscopy 902 X-ray astronomy 854 XML (Document markup language) 750 X-Men (Fictitious characters) 658 X-ray crystallography 614 Xhosa (African people) 469 X-Rays 465 Xhosa language 459 X-ray optics 384 Xiao xue lei 282 Xenobiotics 279 Xiongnu (Asian people) 244 Xi Xia Dynasty (China) 223 Xiao shuo ji 215 Xiang sheng 212 X-ray lithography 208 X-ray sources, Galactic 203 XML (Langage de balisage) 198 X Window System (Computer system) 192 XML 192 X-ray lasers 184 Xenon 167 Xavante Indians 140 XHTML (Document markup language) 126 X rays 120 X-Ray Therapy 118 Xylophone music 115 X-Ray Diffraction 113 Xénophobie 111 Xiang dialects 110 Xiao shuo lei 109 Xenopus laevis 106 Xenografts 95 Xiao xiao shuo 93 Xhosa poetry 92 Xuan ji 92 X ray astronomy 91 Xhosa fiction 90 X-ray telescopes 88 X-ray binaries 86 X-ray microanalysis 81 X-15 (Rocket aircraft) 78 Xeriscaping 71 X-ray microscopes 69 Xin shi 69 X ray sources 68 Xiao shuo 68 Xylem 67 Xerophytes 66 X ray spectra 65 X-ray diffraction 65 Xanth (Imaginary place) 63 Xylene 63 X-ray microscopy 59 Xenarthra 59 Xylophone 58 Xerography 57 Xhosa 57 Xianbei (Asian people) 55 Xing style 54 Xml (Document Markup Language) 53 Xiao shuo jia lei 51 Xue shu si xiang 51 Xenopus 49 Xylophone with orchestra 48 Xenomorphs (Fictitious characters) 47 Xiao shuo yan jiu 47 XHTML (Langage de balisage) 46 Xhosa literature 46 X-ray diffractometer 45 Xian dai shi 45 Xing fa 45 XSLT (Computer program language) 44 XXe siècle 43 X-ray absorption near edge structure 42 X-ray photoelectron spectroscopy 41 XXème siècle 41 Xi ju 36 Xiao shi 36 Xénophobie 36 Xhosa drama 35 Xian qin zhe xue 35 Xerophthalmia 34 Xun gu 34 X-ray bursts 33 Xenarthra, Fossil 33 Xian dai wen xue 33 Xian fa 32 Xikrin Indians 32 XIXe siècle 31 Xi Wang Mu (Taoist deity) 31 Xiao music 31 X chromosome 30 Xbox video games 30 Xiang zhai xiang mu 30 X ray diffraction 29 XYZ Affair, 1797-1798 29 Xangô (Cult) 29