sei
/seɪ/noun
sei is spelled S-E-I: 3 letters. It appears about once in every 1 million words in written English, the 34,504th most frequent word form (wordfreq, 2021 data). As a noun, sei means “A sei whale” (English Wiktionary, September 2026). The plural of sei is seis.
How many letters and syllables are in sei?
| Letters | 3: S-E-I |
|---|---|
| In writing | about once in every 1 million words; the 34,504th most frequent word form |
| Wrong spellings searched | none measured in search |
| Sounds like | |
| Same letters |
Sources: letters and syllables from the English Wiktionary's hyphenation or pronunciation; written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media); rhymes and same-letter words are computed by PlainSpell from its own word list.
How common is sei?
Sei appears about once in every 1 million words in written English, the 34,504th most frequent word form in the list.
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How do you pronounce sei?
- /seɪ/
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Recordings: LL-Q1860_(eng)-Vealhurl-sei.wav, Wikimedia Commons (author and licence on each file's page).
Words people confuse with sei
Sounds like: say (Wiktionary's homophone list; some hold only in some accents).
Sources: English Wiktionary (homophones, alternative spellings).
What rhymes with sei?
No other word on PlainSpell ends in the same sounds as sei.
Spelled with the same letters in another order: sie.
Computed by PlainSpell from the pronunciations in the English Wiktionary (dump of September 2, 2026): a rhyme shares every sound from the last stressed vowel to the end; ordered by written frequency (wordfreq 3.1).
Forms of sei
- seis plural
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
What does sei mean?
The meanings the English Wiktionary records, quoted as written there (source below).
noun
- 1
A sei whale.
noun
- 1
Initialism of solid electrolyte interphase
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Where does sei come from?
From sei whale, from Norwegian seihval, seikval, from sei (“pollock”) + hval (“whale”). Doublet of saithe.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).