system has 5 distinct synonyms spread across 4 of its 9 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. WordNet records no antonym for it — antonymy is a relation between word forms rather than concepts, so it is deliberately sparse.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
instrumentality that combines interrelated interacting artifacts designed to work as a coherent entity
“he bought a new stereo system”
Synonyms, antonyms and the broader and narrower relations for system come from Princeton University’s WordNet. Full sources and licences.
a group of independent but interrelated elements comprising a unified whole
“a vast system of production and distribution and consumption keep the country going”
(physical chemistry) a sample of matter in which substances in different phases are in equilibrium
“in a static system oil cannot be replaced by water on a surface”
a complex of methods or rules governing behavior
“they have to operate under a system they oppose”
an organized structure for arranging or classifying
“he changed the arrangement of the topics”
a group of physiologically or anatomically related organs or parts
“the body has a system of organs for digestion”
a procedure or process for obtaining an objective
“they had to devise a system that did not depend on cooperation”
the living body considered as made up of interdependent components forming a unified whole
“exercise helped him get the alcohol out of his system”
an ordered manner; orderliness by virtue of being methodical and well organized
“his compulsive organization was not an endearing quality”