In the Low Saxon dialect spoken in the eastern parts of the Netherlands, a noaber is a neighbor.
The duties of a noaber were quite extensive. When a new person moved into the neighborhood, they would expect to be invited for a strong drink. They would help with renovations of the house.

Traditional “Brulfteneugers” [wedding inviters], 1933. Collection Gelderland, Open Cultuurdata (CC-BY-SA)
See bruiloft (marriage) for an example of the duties of neighbors during a wedding.
