n.1 Bot. a the part of a plant stem from which one or more leaves emerge. b a knob on a root or branch.
2 Anat. a natural swelling or bulge in an organ or part of the body.
3 Astron. either of two points at which a planet's orbit intersects the plane of the ecliptic or the celestial equator.
4 Physics a point of minimum disturbance in a standing wave system.
5 Electr. a point of zero current or voltage.
6 Math. a a point at which a curve intersects itself. b a vertex in a graph.
7 a component in a computer network.
Derivatives:
nodal adj. nodical adj. (in sense 3).
Etymology: L nodus knot