Actually yes, it is, he is using incorrect terminology for part of my culture, mixing two different tribes and languages together.
Then that's a great way to approach him. You can go up to him after a lecture and tell him you're interested in some of the terminology he's using. Then explain the terminology used in your culture. Offer to send him research if he'd like (in a non-patronising way). If he's getting something culturally wrong he should take the opportunity to learn. Especially if something is culturally inappropriate or offensive.

I suppose part of the issue is what kind of person us he? Is he open to new knowledge?