fission
/ˈfɪʃən/noun, verb
fission is spelled F-I-S-S-I-O-N: 7 letters and 2 syllables. It appears 1.3 times per million words in written English, the 25,070th most frequent word form (wordfreq, 2021 data). As a noun, fission means “The process whereby one item splits to become two” (English Wiktionary, September 2026). The plural of fission is fissions.
How many letters and syllables are in fission?
| Letters | 7: F-I-S-S-I-O-N |
|---|---|
| Syllables | 2 (from its American pronunciation) |
| In writing | 1.3 times per million words; the 25,070th most frequent word form |
| Wrong spellings searched | none measured in search |
Sources: letters and syllables from the English Wiktionary's hyphenation or pronunciation and the CMU Pronouncing Dictionary; written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How common is fission?
Fission appears 1.3 times per million words in written English, the 25,070th 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 fission?
- /ˈfɪʃən/
- /ˈfɪʒən/
Fission has 2 syllables (counted from its American pronunciation in the CMU Pronouncing Dictionary).
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Recordings: LL-Q1860_(eng)-Vealhurl-fission.wav, Wikimedia Commons (author and licence on each file's page).
Forms of fission
- fissions plural, present, singular, he/she/it
- fissioning participle, present
- fissioned participle, past
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
What does fission mean?
The meanings the English Wiktionary records, quoted as written there (source below).
noun
- 1
The process whereby one item splits to become two.
- 2
nuclear fission: The process of splitting the nucleus of an atom into smaller particles.
- 3
The process by which a bacterium splits to form two daughter cells.
verb
- 1
To cause to undergo fission.
- 2
To undergo fission.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Fission in Spanish, French, German and Portuguese
| Language | Words |
|---|---|
| German | Spaltung , Zellteilung , spalten |
| Portuguese | fissão , fissionar |
| Spanish | fisión , fisionar |
| French | fission, scissiparité , fissionner |
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Translations are Wiktionary's, by sense; a linked word has its own PlainSpell page.
Where does fission come from?
Borrowed from Latin fissiōnem, accusative singular of fissiō (“the act of breaking up”), from findō (“split, divide”).
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).