- Xanthophylls
- X
- X-chromosome
- X-copy
- X-rated film
- X-ray
- Xenophobe
- Xenophobia
- Xeroderma
- Xanthophyll
- X windows
- Xanthic
- Xanthic flowers
- Xenogenesis
- Xenoglossia
- Xenophilia
- Xenophyophores
- Xerophthalmia
- Xerophyte
- Xmas
- Xor
- Xylocopa
- Xylophone
- Xanthippe
- X mark
- Xed out
- Xenomaniac
- Xerophytes
- Xylography
- Xymophobia
- X modem
- X-axis
- Xcon
- Xenial
- Xenobombulate
- Xenogamy
- Xenon
- Xerography
- Xerophilous
- Xerox
- Xhosa
- Xoxo
- Xylem
- Xylene
- Xylol