(idiomatic) something that has a sudden and usually unpleasant effect on someone.

(politics) The global constellation of states and their relations among each other. / Ellipsis of International System of Units. (alternative letter-case form)

plural of system architecture

(software, system theory) The conceptual model that defines the behavior, structure, and more views of a system.

An electronic system used to reproduce sound. / The set of speech sounds that make up a language; a phonology.

(law) A system of law in which advocates represent the prosecution and the defence and an impartial person (judge) or people (jury) determine the truth of the matter

(physics) A localized physical system consisting of interacting components, called degrees of freedom

The system of fraternities and sororities in North American colleges.

(computing) A new computer part that has been removed from an unused, previously assembled system.

Alternative letter-case form of Solar System