- Xanadu
- Xanthippe
- Xavier
- xci
- xcii
- xciv
- xcix
- xcvi
- xcvii
- Xe
- XEmacs
- Xenakis
- Xenia
- xenon
- xenophobe
- xenophobia
- xenophobic
- Xenophon
- xerographic
- xerography
- Xerox
- Xerxes
- Xhosa
- xi
- Xi'an
- Xian
- Xiaoping
- xii
- xiii
- Ximenes
- Xingu
- Xiongnu
- xiv
- xix
- XL
- Xmas
- XML
- Xochipilli
- xor
- xref
- xreffed
- xreffing
- xrefs
- XS
- xterm
- Xuzhou
- xv
- xvi
- xvii
- xviii
- xx
- xxi
- xxii
- xxiii
- xxiv
- xxix
- XXL
- xxv
- xxvi
- xxvii
- xxviii
- xxx
- xxxi
- xxxii
- xxxiii
- xxxiv
- xxxix
- xxxv
- xxxvi
- xxxvii
- xxxviii
- xylem
- xylene
- xylophone
- xylophonist