We found 23 dictionaries that define the word sei:

General (11 matching dictionaries)

1. sei: Merriam-Webster
2. sei: Oxford Learner's Dictionaries
3. sei: American Heritage Dictionary of the English Language
4. sei: Collins English Dictionary
5. Sei, sei, sei: Wordnik
6. sei: Wiktionary
7. SEI: Dictionary.com
8. SEI, Se'i, Sei (film), Sei: Wikipedia, the Free Encyclopedia
9. sei: AllWords.com Multi-Lingual Dictionary
10. SEI: Stammtisch Beau Fleuve Acronyms
11. sei: TheFreeDictionary.com

Computing (2 matching dictionaries)

12. SEI: Free On-line Dictionary of Computing
13. SEI: Encyclopedia

Medicine (2 matching dictionaries)

14. online medical dictionary (No longer online)
15. Sleep Terms (No longer online)

Miscellaneous (3 matching dictionaries)

16. SEI: Acronym Finder
17. SEI: Three Letter Words with definitions
18. AbbreviationZ (No longer online)

Religion (1 matching dictionary)

19. Basic Terms of Shinto (No longer online)

Science (1 matching dictionary)

20. Electrochemistry Dictionary (No longer online)

Slang (2 matching dictionaries)

21. sei: Green’s Dictionary of Slang
22. sei: Urban Dictionary

Tech (1 matching dictionary)

23. DOD Dictionary of Military Terms: Joint Acronyms and Abbreviations (No longer online)

Definitions from Wiktionary (sei) ▸ noun:  A sei whale. Similar: sei whale, pollack whale, whalefish, seaswine, whalefisher, social whale, whalekind, whalespeak, sea goose, whalesong, more... Phrases: sei whales, sei whale, sei cmm, SEI Investments Company, Kangalal Kaidhu Sei, more... Adjectives: invest, forensic, animal, visual, informativo, boletim, gross, ital, yon, current, insect ▸ Words similar to sei ▸ Usage examples for sei ▸ Idioms related to sei ▸ Wikipedia articles (New!) ▸ Popular adjectives describing sei ▸ Words that often appear near sei ▸ Rhymes of sei ▸ Invented words related to sei