# Longest English Words

> English word ranking · 50 entries · ranked by letters

1. **electroencephalography** — 22 letters
2. **internationalization** — 20 letters
3. **uncharacteristically** — 20 letters
4. **institutionalization** — 20 letters
5. **electrophysiological** — 20 letters
6. **immunohistochemistry** — 20 letters
7. **compartmentalization** — 20 letters
8. **counterrevolutionary** — 20 letters
9. **tetrahydrocannabinol** — 20 letters
10. **hypercholesterolemia** — 20 letters
11. **acetylcholinesterase** — 20 letters
12. **phosphatidylinositol** — 20 letters
13. **counterintelligence** — 19 letters
14. **immunohistochemical** — 19 letters
15. **interdenominational** — 19 letters
16. **professionalization** — 19 letters
17. **disproportionately** — 18 letters
18. **characteristically** — 18 letters
19. **disenfranchisement** — 18 letters
20. **neuropsychological** — 18 letters
21. **oversimplification** — 18 letters
22. **unconstitutionally** — 18 letters
23. **interconnectedness** — 18 letters
24. **Thiruvananthapuram** — 18 letters
25. **neurodevelopmental** — 18 letters
26. **gastroenterologist** — 18 letters
27. **immunofluorescence** — 18 letters
28. **transubstantiation** — 18 letters
29. **psychopharmacology** — 18 letters
30. **lipopolysaccharide** — 18 letters
31. **neurophysiological** — 18 letters
32. **evapotranspiration** — 18 letters
33. **histocompatibility** — 18 letters
34. **interchangeability** — 18 letters
35. **interdisciplinary** — 17 letters
36. **indistinguishable** — 17 letters
37. **telecommunication** — 17 letters
38. **institutionalized** — 17 letters
39. **intergovernmental** — 17 letters
40. **industrialization** — 17 letters
41. **multidisciplinary** — 17 letters
42. **counterproductive** — 17 letters
43. **commercialization** — 17 letters
44. **misrepresentation** — 17 letters
45. **constitutionality** — 17 letters
46. **intergenerational** — 17 letters
47. **industrialisation** — 17 letters
48. **misinterpretation** — 17 letters
49. **neurodegenerative** — 17 letters
50. **decriminalization** — 17 letters

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA) and an open word-frequency list. Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/rankings/longest-words