World Fantasy was a blast, and my panel went well. In it, we talked a bit about anachronisms in speech and dialogue: How you want to try to avoid terms or slang that hadn’t come into use at the time of your novel as well as words that have a strong association with a culture that your culture wouldn’t have had contact with.
You should all go check out Mary Robinette Kowal’s list of the eight worst anachronisms in fantasy novels, though. She lists some fun doozies.