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75 Science Words That Start With X by Grade level
Exploring science can be exciting—even with the tricky letter “X”! This list breaks down Science Words that Start With X by grade level to help students, educators, and curious minds expand their vocabulary one “X” at a time.
Science Words That Start With X – Elementary (Grades K–5)
| Word | Definition |
|---|---|
| X-ray | A form of energy that can pass through objects; used in medical imaging. |
| X-axis | The horizontal line in a graph. |
| Xenon | A gas used in lights and scientific devices. |
| Xylem | Plant tissue that carries water. |
| Xerophyte | A plant adapted to dry environments. |
| Xeriscape | Landscaping with minimal water use. |
| Xanthophyll | A yellow pigment in plants. |
| Xenops | A type of bird studied in biology. |
| Xylophone | A musical instrument used in sound studies. |
| Xiphosuran | An ancient sea creature, like the horseshoe crab. |
| Xanthic | Relating to yellow color. |
| Xenodochium | A shelter for strangers, studied in historical biology contexts. |
| Xenagogue | A guide, especially for foreign guests—used metaphorically in biology. |
| Xenogenesis | Birth of offspring unlike the parent. |
| Xenolithic | Containing rock fragments from outside sources. |
| Xenic | Containing foreign species. |
| Xeransis | A condition of extreme dryness. |
Science Terms That Start With X – Middle School (Grades 6–8)
| Word | Definition |
|---|---|
| Xenobiotic | A foreign chemical substance in a body or environment. |
| Xenogenesis | Formation of new organisms that are genetically different. |
| Xeric | Related to dry habitats or climates. |
| Xenotransplantation | Organ transplant between species. |
| Xenocryst | A crystal not formed in the rock it’s found in. |
| Xenolith | A rock fragment in a different host rock. |
| X-ray Diffraction | Studying materials by observing how X-rays scatter. |
| Xenobiology | Study of synthetic or alien life forms. |
| Xenochemistry | Study of non-Earth-like chemistry. |
| Xenocentrism | Belief that other cultures are superior, used in anthropology. |
| Xenogenic | Derived from a different species. |
| Xerophthalmia | Eye disease caused by vitamin A deficiency. |
| Xenogamy | Pollination between flowers of different plants. |
| Xerarch | Succession beginning in a dry area. |
| Xanthate | Chemical used in processing minerals. |
| Xanthene | A chemical compound used in dyes. |
| Xenoviral | Related to viruses from other species. |
Science Words That Start With X – High School (Grades 9–12)
| Word | Definition |
|---|---|
| X-ray Crystallography | Method to determine the atomic structure of crystals. |
| X-chromosome | Sex chromosome present in both men and women. |
| X-linked Traits | Traits controlled by genes on the X-chromosome. |
| Xenotransfusion | Transfusing blood from one species to another. |
| Xenon Flash | Bright flash used in photography and medical devices. |
| X-band Radar | Radar technology using high-frequency waves. |
| X-ray Spectroscopy | Technique to analyze material composition. |
| Xenovirus | Virus that infects non-native hosts. |
| Xylose | A sugar found in plant cells. |
| Xenotime | Mineral used in age dating rocks. |
| Xanthoma | Fat buildup in the skin studied in health science. |
| Xylitol | Sugar substitute studied in dental science. |
| Xeroderma | Condition of dry skin due to genetics. |
| Xenodiagnosis | Diagnosis by exposing suspected parasite to a host. |
| Xenopsylla | Genus of fleas important in disease studies. |
| Xerogel | A form of dried gel used in chemistry. |
| Xenoplastic | Involving grafting tissue from different species. |
Science Terms That Start With X – College Level
| Word | Definition |
|---|---|
| X-ray Photoelectron Spectroscopy | Surface analysis technique for materials. |
| Xenobiotic Metabolism | Study of how foreign compounds are processed in the body. |
| X-ray Astronomy | Study of space objects via X-rays. |
| Xylology | The study of wood and woody tissues. |
| Xenon Isotopes | Used in nuclear and planetary science. |
| Xanthoproteic Reaction | Chemical test for detecting proteins. |
| Xenocatalysis | Catalysis involving external catalysts. |
| Xyloglucan | A type of plant cell wall polysaccharide. |
| Xiphoid Process | The small bony tip of the sternum. |
| Xenotropic Virus | A virus that only replicates in foreign species. |
| Xylanase | Enzyme that breaks down xylan in plants. |
| Xenogeneic Cells | Cells derived from a different species. |
| Xenovector | Genetic carrier from a foreign species. |
| Xenon Tetroxide | A reactive compound of xenon in chemistry. |
| Xenoradiation | Radiation from external or non-standard sources. |
| Related: 60 Science Words that Start With Q
Conclusion
Science words that start with X may be rare, but they’re powerful tools for expanding vocabulary and curiosity. Whether you’re a student, teacher, or lifelong learner, this list offers a fun and educational way to explore science through the alphabet—starting with the extraordinary letter X.
