Hvorfor hedder det en sinuskurve?

…fordi kurven er baseret på sinusfunktionen

Etymologically, the word sine derives from the Sanskrit word for chord, jiva*(jya being its more popular synonym). This was transliterated in Arabic as jiba ???????, abbreviated jb ?????? . Since Arabic is written without short vowels, "jb" was interpreted as the word jaib ???????, which means "bosom", when the Arabic text was translated in the 12th century into Latin by Gerard of Cremona. The translator used the Latin equivalent for "bosom", sinus (which means "bosom" or "bay" or "fold").[8][9] The English form sine was introduced in the 1590s.

^{_{https://en.wikipedia.org/wiki/Sine}}

Sinus betyder krumning, bue, kurve, (hav)bugt.
På klassiske landkort vil en havbugt hedde Sinus .......
F.eks. Det Røde Hav hedder Sinus Arabicus.
Jammerbugten, i Nordvestjylland, kommer da til at hedde  Sinus Lamentabilis.
Den sidste udlægning står dog for min egen regning :)