Bet-al-Geuse: The house of Geuse.
The armpit is called "the house of the shoulder" in Semetic languages, so "house of Geuse" could be understood as "armpit of Geuse". Actually, the "Bet" is thought to be a misreading of "Yad" (very similar letters in Arabic) and the name was originally "Yad al Jauza" or the "hand of Jauza". I've yet to discover who Jauza is / was but I still do have some resources to check, just not the time!
If you or your lecturer are interested in any other star names, you can contact me. My Gmail username is the same as my /. username. In fact, I'm leaving later today for a ten day vacation to the arctic circle to see the northern nights for the first time, so you'll have to wait for an answer!