What does "cosine" mean?

In a right triangle, the ratio of the length of the side adjacent to an acute angle to the length of the hypotenuse. Symbol: cos

Cosine

Common synonyms include: cos, argument, cosine function, cosine measure, cosine similarity, element.

/ˈkoʊ.saɪn/ noun

noun ·Rare ·Advanced level

Noun

1
In a right triangle, the ratio of the length of the side adjacent to an acute angle to the length of the hypotenuse. Symbol: cos
2
ratio of the adjacent side to the hypotenuse of a right-angled triangle wordnet

"The functions sine and cosine take values between -1 and 1 (-1 and 1 included)."

From co- + sine, short for complementi sinus in Latin, meaning “sine of the complement”. Doublet of cosinus.