Origin of the word sine

The word sine is derived from the Latin sinusmeaning "bay" or "fold" from an erroneous (via Arabic) translation of Sanskrit jiva, and its variant jya.

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 of Chester and Gherardo of Cremona in 12th-century Toledo confused jiba with jaibwhich 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).