What are the Wesen terms for "normal" people, and normal people who know about the Wesen?
Kehrseite seems to be their word for normal humans, and Kehrseite-Schlich-Kennen is their word for people who know about wesen. I remembered them saying something in The Good Shepard, but it took me awhile to find the spelling. Turns out it was right there on the wiki: http://grimm.wikia.com/wiki/Category:Human. Oh well.
First of all, as a German native speaker I have to say that the writers of Grimm haven't consulted a single German speaker or dictionary for that matter. Words are thrown together randomly, don't make sense or don't even exist. Having said that, I love the show. Now, "Kehrseite" has been used to define "normal humans" (though in fact it means "Butt/ Rear end" and "Kehrseite-Schlich-Kennen" is complete gibberish).