sine
/saɪn/noun
sine is spelled S-I-N-E: 4 letters and one syllable. It appears 1.3 times per million words in written English, the 25,367th most frequent word form (wordfreq, 2021 data). As a noun, sine means “In a right triangle, the ratio of the length of the side opposite an angle to the length of the hypotenuse” (English Wiktionary, September 2026). The plural of sine is sines.
How many letters and syllables are in sine?
| Letters | 4: S-I-N-E |
|---|---|
| Syllables | 1 (from its American pronunciation) |
| In writing | 1.3 times per million words; the 25,367th most frequent word form |
| Wrong spellings searched | none measured in search |
| Pairs people search | |
| Sounds like | |
| Same letters |
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); Bing searches in the United States: the average month from September 2025 to August 2026 (Microsoft Advertising keyword data through DataForSEO, read September 30, 2026); rhymes and same-letter words are computed by PlainSpell from its own word list.
How common is sine?
Sine appears 1.3 times per million words in written English, the 25,367th 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 sine?
- /saɪn/
Sine has one syllable (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-sine.wav, LL-Q1860_(eng)-Wodencafe-sine.wav, Wikimedia Commons (author and licence on each file's page).
Words people confuse with sine
Word pairs people search, with the monthly searches for “a vs b” (G: Google, B: Bing, United States).
Sounds like: sign, syne (Wiktionary's homophone list; some hold only in some accents).
Sources: Google and Bing searches (September 2025 to August 2026, through DataForSEO); English Wiktionary (homophones, alternative spellings).
What rhymes with sine?
No other word on PlainSpell ends in the same sounds as sine.
Spelled with the same letters in another order: ensi.
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 sine
- sines plural
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
What does sine mean?
The meanings the English Wiktionary records, quoted as written there (source below).
noun
- 1
In a right triangle, the ratio of the length of the side opposite an angle to the length of the hypotenuse.
noun
- 1
Acronym of short interspersed element, a type of retrotransposon in genomics.
- 2
Acronym of selective inhibitors of nuclear export, a drug for epithelioid sarcoma.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Sine in Spanish, French, German and Portuguese
In the sense trigonometric function:
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 sine come from?
Borrowed from Latin sinus (“curve, bend; bosom”), a translation of Arabic جَيْب (jayb, “bosom”), a misidentification of the notation جيب (j-y-b), written without vowel diacritics, standing for Arabic جِيبَ (jība, “sine”), in turn from Sanskrit ज्या (jyā, “sine, chord, bowstring”) through the similar Sanskrit जीव (jīva, “sine, chord, life, existence”). Doublet of sinus.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).