Typically, at least in the northeastern part of the United States, one may find a large political entity which contains small groups of population centers having local names which differ from the name of the larger political entity. In my case I live in a legal town in Connecticut which contains places such as Jordan Village, Oswegatchie, etc. The political center of the town is denominated "Waterford Twn" while all the other places fall under the "Waterford" label. I am pretty certain it is this way because of historical reasons.
It stands for "Township" do a Google search. There is no simple explanation. It is somewhat like a "county" but different.
In Pennsylvania where I grew up there were usually many townships in any given county and they were separate political entities. To make it more confusing there were other political/geographic entities which also were parts of counties. Counties were also political.
However, here in Connecticut we have no Townships, just Towns, and some would argue that we have cities but they are really just grown up towns! :) We also have counties in Connecticut which are sort of State government entities.
So, in Connecticut , notwithstanding Google, "Twn" does not mean township.
