Betelgeuse is one of the best known star names in the sky and it is a mistake. The Arabic is yad al-jauza, the hand of al-Jauza; medieval transmission misread the initial ya as a ba, and the corrupted form entered European catalogues and stayed. Rigel is cleaner: rijl al-jauza, her foot.
Al-Jauza is a female figure of the pre-Islamic Arabian sky occupying the stars Greece made a hunter. The name is generally connected with a root meaning the middle, and she was understood as standing across the middle of the sky or as the central one among her people. There is a second figure, al-jauza of the sky and al-jauza the sister, and the accounts vary.
What survives of her is the two star names, and they survive because Arabic astronomical writing was the channel through which Ptolemy reached medieval Europe. Translators took the coordinates and the Greek figures and, star by star, the Arabic descriptive names, and the descriptive names stuck even where the figure they described was discarded.
The sky is full of this. Deneb is the tail, Fomalhaut the mouth of the fish, Altair the flying eagle, and in each case the name is a body part of a figure the modern list either kept or lost. Al-Jauza is the clearest case of a figure entirely lost and thoroughly named.