What is the meaning of “Mensch” when used between friends or family members?

Question

I met a long-time couple recently, and I frequently heard the wife calling her husband "Mensch."

As an example, at one point she asked

"Was ist das, Mensch?"

and at another

"Ach, Du Mensch!"

It was said in an exasperated, yet still clearly affectionate, manner.

(I'd seen it translated in other contexts — e.g., in a libretto for Alban Berg's Wozzeck — as an insult; hence my confusion as to what the word means.)

Answer 1

I never heard that in this way you conjecture. And I can hardly imagine that this is just regional.

Mensch is used as interjection, especially when you're surprised about something.

It means gosh, gee, ... ^LEO

Alternatively you can say Menschenskind(er). ^{LEO AGAIN}

Both sentence you give sounds odd to me. Maybe they fit in context, but I would use it that way:

Mensch, daran hätte ich nicht gedacht.

Note also Mensch Meier.

Answer 2

I would say, that this is just a personal habit of your friend, it's neither used in regular German, nor did I ever heard it colloquially.

But I guess the best way to find out is asking her...