here: also as equivalent to node :
http://www.csun.edu/~sd1229/690H/New Urbanism-Crime-and the ...-OR: (physics) An attractor is a set towards which a dynamical system evolves over time. That is, points that get close enough to the attractor remain close even if slightly disturbed¨. This is a simple definition from Wikipedia. The geometric result of the attractor image is a fractal.
Conceptually, some cities or neighborhoods have ¨attractors¨, in which inhabitants are a complex system and no matter what, they keep close to a certain attractor.