The word sine is derived from the Latin *sinus*, which means "bay" or "fold", which has nothing to do with the mathematical concept of sine we know. This was from an erroneous (via Arabic) translation of Sanskrit *jiva*, and its variant *jya*. The mathematician Aryabhata used the term *ardha-jiva* ("half-rope"), which was abbreviated to *jiva* and then transliterated by the Arabs as *jiba*. European translators such as Robert de Chester and Gherard de Cremona in twelfth-century Toledo confused *jiba* with *jaib*which means "bay" probably because *jiba* and *jaib* they are written the same way in Arabic script (this writing system in one form does not provide the reader with complete information about the vowels).

Some claim that the word *sinus* it first appeared in a translation of al-Khowarizmi's Algebra by Gherard de Cremona. Around the year 1150, when he made his translations from Arabic, he replaced Arabic *jaib* by its Latin equivalent, *sinus*where our present word sine came from.

Historian and mathematician Boyer believes that the first appearance of *sinus* occurred in an 1145 translation when Robert de Chester came to translate the technical word *jiba* and seems to have confused her with *jaib*. Since then, the term *sinus* It was adopted by European mathematicians in their own writings and began to appear in several sentences.

In the English language, the word came in two forms: *sinus* and *sine*. The Oxford Dictionary has quotations for both words meaning "gulf" or "bay", but describes the latter use as obsolete, with the English word *sine* survived only in the mathematical sense.