noun

1. a set or arrangement of things so related or connected as to form a unity or organic whole a solar system, school system, system of highways
2. a set of facts, principles, rules, etc. classified or arranged in a regular, orderly form so as to show a logical plan linking the various parts
3. a method or plan of classification or arrangement
4. 1. an established way of doing something; method; procedure
   2. orderliness or methodical planning in one's way of proceeding
5. 1. the body considered as a functioning organism
   2. a number of bodily organs acting together to perform one of the main bodily functions the digestive system
6. a related series of natural objects or elements, as cave passages, rivers, etc.
7. Chem. a group of substances in or approaching equilibrium: a system with two components, phases, or variables is called binary, one with three, ternary, etc.
8. Comput.
   1. an organization of hardware and software, often together with personnel, that function together as a unit
   2. operating system: often in the pl. form when used attributively a system programmer, systems software
9. Crystallography any of the seven divisions (cubic, tetragonal, hexagonal, rhombohedral, orthorhombic, monoclinic, and triclinic) in which all crystal forms can be placed, based on the degree of symmetry of the crystals
10. Geol. a major division of stratified rocks consisting of the rocks laid down during a geologic period

Etymology: LL systema < Gr systēma (gen. systēmatos) < synistanai, to place together < syn-, together + histanai, to set: see stand