Meanings
nouncosine (plural cosines)
plural cosines
- mathematicsIn a right triangle, the ratio of the length of the side adjacent to an acute angle to the length of the hypotenuse. Symbol: cos
Synonyms & antonyms
nounratio of the adjacent side to the hypotenuse of a right-angled triangle
Similar
Synonym sets from Open English WordNet, CC BY 4.0.
Origin
- Proto-Indo-European*ḱe?
- Proto-Indo-European*ḱóm
- Proto-Italic*kom
- Proto-Italic*kom-
- Latincon-
- Latinco-
- Englishco-
- Proto-Indo-European*sinos
- Proto-Italic*sinus
- Arabicجِيبَ (jība)
- Latinsinus
- Englishsine
- Englishcosine
From co- + sine, short for complementi sinus in Latin, meaning “sine of the complement”. Doublet of cosinus.
Full word history & related roots →Translations
Arabic جَيْب تَمَام
- جَيْب تَمَام (jayb tamām)trigonometric function
Basque kosinu
- kosinutrigonometric function
Bulgarian ко́синус
- ко́синус (kósinus)trigonometric function
Catalan cosinus
- cosinustrigonometric function
Chinese Mandarin 餘弦 /余弦
- 餘弦 /余弦 (yúxián)trigonometric function
Czech kosinus
- kosinustrigonometric function
Dutch cosinus
- cosinustrigonometric function
Esperanto kosinuso
- kosinusotrigonometric function
Finnish kosini
- kosinitrigonometric function
French cosinus
- cosinustrigonometric function
German Kosinus
- Kosinustrigonometric function
Greek συνημίτονο
- συνημίτονο (synimítono)trigonometric function
Hebrew קוסינוס
- קוסינוס (cosinus)trigonometric function
Hungarian koszinusz
- koszinusztrigonometric function
Icelandic kósínus
- kósínustrigonometric function
Irish comhshíneas
- comhshíneastrigonometric function
Italian coseno
- cosenotrigonometric function
Japanese コサイン, 余弦
- コサイン (kosain)trigonometric function
- 余弦 (yogen)trigonometric function
Korean 코사인, 여현
- 코사인 (kosain)trigonometric function
- 여현 (yeohyeon)trigonometric function
Latvian kosinuss
- kosinusstrigonometric function
Malay kosinus
- kosinustrigonometric function
Māori whenu
- whenutrigonometric function
Norwegian Bokmål cosinus
- cosinustrigonometric function
Polish cosinus, kosinus
- cosinustrigonometric function
- kosinustrigonometric function
Portuguese co-seno, cosseno
- co-senotrigonometric function
- cossenotrigonometric function
Romanian cosinus
- cosinustrigonometric function
Russian ко́синус
- ко́синус (kósinus)trigonometric function
Slovak kosínus
- kosínustrigonometric function
Spanish coseno
- cosenotrigonometric function
Swedish cosinus
- cosinustrigonometric function
Tagalog kasinway
- kasinwaytrigonometric function
Tamil துணைசெவ்வளை
- துணைசெவ்வளை (tuṇaicevvaḷai)trigonometric function
Thai โคไซน์
- โคไซน์ (koo-saai)trigonometric function
Turkish kosinüs
- kosinüstrigonometric function
Ukrainian ко́синус
- ко́синус (kósynus)trigonometric function
Vietnamese côsin
- côsintrigonometric function
Rhymes & wordplay
Sounds the same
Anagrams
Cite this entry
APA
cosine. (n.d.). In WatkinsX Dictionary. Retrieved November 3, 2026, from https://dictionary.watkinsx.com/word/cosine
MLA
“cosine.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/cosine. Accessed November 3, 2026.
Chicago
WatkinsX Dictionary, s.v. “cosine,” accessed November 3, 2026, https://dictionary.watkinsx.com/word/cosine.
Source: cosine on Wiktionary, CC BY-SA 4.0.