| X Japan | X Japan |
| X secolo | X wiek |
| X Window System | X Window System |
| X-Files | Z Archiwum X |
| X-Men | X-Men |
| X-wing | X-wing |
| Xabi Alonso | Xabi Alonso |
| Xai-Xai | Xai-Xai |
| Xaignabouli | Sayaboury |
| Xaisomboun | Prowincja Saysomboun |
| XAML | Extensible Application Markup Language |
| Xanadu | Xanadu |
| Xanana Gusmão | Xanana Gusmão |
| Xander Harris | Alexander Harris |
| Xanten | Xanten |
| Xanthi | Ksanthi |
| Xanthium | Rzepień |
| Xanthos | Ksantos |
| Xantofille | Ksantofile |
| Xavi | Xavi |
| Xbill | XBill |
| XChat | XChat |
| XD-Picture Card | Karta pamięci xD |
| Xekong | Prowincja Xekong |
| Xenartha | Szczerbaki |
| Xenarthra | Szczerbaki |
| Xenia | Ksenia |
| Xenia di San Pietroburgo | Ksenia z Petersburga |
| xeno | ksenon |
| xeno- | kseno- |
| xenofobia | ksenofobia |
| Xenoglossia | Glosolalia |
| Xenomorfo | Ksenomorf |
| xenon | ksenon |
| Xenophon Zolotas | Xenophon Zolotas |
| Xenotime- | Ksenotym |
| Xenu | Xenu |
| Xeon | Xeon |
| Xeres | Sherry |
| Xerocomus | Podgrzybek |
| Xerocomus badius | Podgrzybek brunatny |
| xerocopiare | kserować |
| Xerogel | Kserożel |
| Xerox Alto | Alto |
| Xerox Corporation | Xerox |
| Xerox Palo Alto Research Center | Xerox PARC |
| Xfce | Xfce |
| Xgl | XGL |
| XHTML | XHTML |
| Xi | Ksi |
| XI dinastia egizia | XI dynastia |
| XI secolo | XI wiek |
| XIA | Dynastia Xia |
| Xiamen | Xiamen |
| Xiangkhoang | Prowincja Xieng Khouang |
| Xiangqi | Xiangqi |
| Xiaolin Showdown | Xiaolin - pojedynek mistrzów |
| Xie Jun | Xie Jun |
| XII dinastia egizia | XII dynastia |
| XII secolo | XII wiek |
| XIII secolo | XIII wiek |
| xilene | ksylen |
| Xilitolo | Ksylitol |
| xilo- | ksylo- |
| xilofono | ksylofon |
| xilolo | ksylen |
| xilosio | ksyloza |
| Xindi | Xindi |
| Xingu | Xingu |
| Xining | Xining |
| Xinjiang | Sinkiang |
| Xinjiang Uygur | Sinkiang |
| Xiongnu | Xiongnu |
| Xipe Totec | Xipe Totec |
| Xiphias gladius | Włócznikowate |
| Xiphophorus helleri | Mieczyk Hellera |
| Xiphos | Xiphos |
| Xiuhtecuhtli | Xiuhtecuhtli |
| XIV secolo | XIV wiek |
