Betelgeuse

Be·tel·geuse (bēt’l-jo͞oz′, bĕt’l-jœz′)

n. ▸ A bright-red intrinsic variable star, 527 light years from Earth, in the constellation Orion.

╂ [French Bételgeuse, ultimately from Arabic yad al-jawzā' : yad, hand; see yd + al-, the + jawzā', Gemini (later also used for Orion) (perhaps from jawz, middle (Gemini perhaps originally being so called because it crossed the middle of the sky, and Orion later being so called because of the three bright stars in the middle of the constellation, forming Orion's belt) , from jāza, to pass through; see gwz).]

Word History: The history of the curious star name Betelgeuse is a good example of how scholarly errors can creep into language. The story starts with the pre-Islamic Arabic astronomers, who called the star yad al-jawzā', "hand of the jawzā'." The jawzā' was their name for the constellation Gemini. After Greek astronomy became known to the Arabs, the word came to be applied to the constellation Orion as well. Some centuries later, when scribes writing in Medieval Latin tried to render the word, they misread the y as a b (the two corresponding Arabic letters are very similar when used as the first letter in a word), leading to the Medieval Latin form Bedalgeuze. In the Renaissance, another set of scholars trying to figure out the name interpreted the first syllable bed- as being derived from a putative Arabic word *bāṭ meaning "armpit." This word did not exist; it would correctly have been ibṭ. Nonetheless, the error stuck, and the resultant etymologically "improved" spelling Betelgeuse was borrowed into French as Bételgeuse, whence English Betelgeuse.