X-rays 4,252
Xenophobia 1,627
X-ray spectroscopy 902
X-ray astronomy 854
XML (Document markup language) 750
X-Men (Fictitious characters) 663
X-ray crystallography 614
Xhosa (African people) 470
X-Rays 465
Xhosa language 460
X-ray optics 384
Xiao xue lei 281
Xenobiotics 279
Xiongnu (Asian people) 249
Xi Xia Dynasty (China) 219
Xiao shuo ji 219
Xiang sheng 211
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
Xénophobie 114
X-Ray Diffraction 112
Xiang dialects 110
Xiao shuo lei 109
Xenopus laevis 106
Xenografts 96
Xhosa poetry 92
X ray astronomy 91
Xhosa fiction 90
X-ray telescopes 88
X-ray binaries 86
X-ray microanalysis 81
X-15 (Rocket aircraft) 79
Xeriscaping 71
X-ray microscopes 69
X ray sources 68
Xylem 67
Xerophytes 66
X ray spectra 65
X-ray diffraction 65
Xanth (Imaginary place) 63
Xuan ji 63
Xylene 63
X-ray microscopy 59
Xenarthra 59
Xylophone 58
Xerography 57
Xhosa 56
Xianbei (Asian people) 55
Xing style 53
Xml (Document Markup Language) 53
Xiao shuo jia lei 51
Xenopus 49
Xylophone with orchestra 48
Xenomorphs (Fictitious characters) 47
XHTML (Langage de balisage) 46
Xhosa literature 46
X-ray diffractometer 45
Xiao shuo yan jiu 45
Xue shu si xiang 45
XSLT (Computer program language) 44
XXe siècle 43
Xiang cun 43
X-ray absorption near edge structure 42
Xin shi 42
Xing fa 42
X-ray photoelectron spectroscopy 41
XXème siècle 41
Xian dai shi 39
Xiao shuo 39
Xénophobie 37
Xiao shi 36
Xhosa drama 35
Xerophthalmia 34
X-ray bursts 33
Xenarthra, Fossil 33
Xikrin Indians 32
Xun gu 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
Xangô (Cult) 29
Xavante language 29
XYZ Affair, 1797-1798 28
Xian qin zhe xue 27
Xylitol 27
X-33 reusable launch vehicle 26