complex system
system composed of many interacting components
complex adaptive system
system in which a perfect understanding of the individual parts does not automatically convey a perfect understanding of the whole system's behavior
chaotic system
dynamical system that is sensitive to initial conditions, topologically mixing, and with dense periodic orbits
organization
social entity established to meet needs or pursue goals
nonlinear system
one whose behaviour cannot be expressed as a sum of the behaviour of its parts (or of their multiples)