node

1a :  a pathological swelling or enlargement (as of a rheumatic joint)b :  a discrete mass of one kind of tissue enclosed in tissue of a different kind

2 :  an entangling complication (as in a drama) :  predicament

3 :  either of the two points where the orbit of a planet or comet intersects the ecliptic; also :  either of the points at which the orbit of an earth satellite crosses the plane of the equator

4a :  a point, line, or surface of a vibrating body or system that is free or relatively free from vibratory motionb :  a point at which a wave has an amplitude of zero

5a :  a point at which subsidiary parts originate or centerb :  a point on a stem at which a leaf or leaves are insertedc :  a point at which a curve intersects itself in such a manner that the branches have different tangentsd :  vertex 1b