| Word | Definition |
| xanth- | yellow |
| xen/o | foreign |
| xenophobia | Intense or irrational dislike or fear of anything that is strange or foreign, particularly of strange people. |
| xer/o | dry |
| xeroderma | An inherited condition characterized by an extreme sensitivity to ultraviolet rays from sunlight. |
| xerophthalmia | Severe dry eyes caused by a malfunction of the tear glands. |
| xiph/o | sword shaped, xiphoid |