haus is a house. "-hausen" is an ending that's often used for towns' names. I can't think of an equivalent in english, but something similar would be "Beverly Hills", "Christchurch", "Bridgeport" or maybe even the "ton"-ending that you have (Torrington), though I don't know where the latter comes from (does it derive from "town"?).
While all of these are named according to specialties about the place (church, hills, port), in german, "hause" is more like an ending that means "a collection of houses" and, I think, it's rather old german.
A better translation may also be something like in "Rushville", the "ville" ending.
As an example, "Entenhausen" is, in German, the name of the place that Donald Duck lives in, where "Enten" means "ducks", so it is the "Duckville" or "Duckton".

Correct me if I'm wrong anywhere here...

Now, the "Groß" simply means "large" (ß is pronounced just like an s), so it's something like "Largeton" or "Bigville".
"Groet" means asolutely nothing to me, although it reminds me of both "Kröte" (=toad) and "Goethe" (= Johann Wolfgang von Goethe, probably one of the two most famous German poets, 1749-1832, from the "storm and stress" epoch (or do you say "era"?) and later "classical" era.)

Does that answer your question?

Sorry for off topic there. But I thought, Guido Weserwelle speaks german to non-german people, so why shouldn't I?