Same here. That's what it meant when I was growing up 40 years ago, but you don't here anyone saying this any more. I asked my son and he only said "unknown". It's interesting because foreign(not from the US) people, food, and customs are pretty normal. I would say they are not unknown. So I want to hope that proper usage of the word, not politically correctness has pushed it away. BTW: If you think your usage is normal, it might be. I am not your target audience.