For what it's worth, I also came here because I had never heard of vihara before. The course would probably be more user-friendly if it were translated as "monastery". But, of course, your mileage may vary.
Actually I think it is more correctly a Sanskrit word. I have a Bhuddist friend here in Melbourne, Australia and he talks about going to the Bhuddist monastery. I've never heard or read the word vihara.