(computing) The software associated with an operating system and supporting utilities, database systems etc.

(logic) A formal system.

(logic) The grouping of a formal language and a set of inference rules and/or axioms.

(ethics) A particular set of consistent ethical principles.

(artificial intelligence) A type of artificially intelligent software system, which stores expertise concerning some subject matter in a knowledge base and attempts to answer questions or solve problems in a manner which simulates the thought processes of a human expert.

(computing) An old computer system or application program that continues to be used because the user (typically an organization) does not want to replace or redesign it.

(zoology) The system of connected water channels that is unique to sponges (Porifera). / (zoology, dated) The hydrostatic skeleton of certain marine gastropods.

The Copernican system of astronomy, erroneously attributed to Pythagoras.

(Philippines) Corruption involving patronage, nepotism and favoritism, especially in politics and government.

Synonym of star system