a set of things working together as parts of a mechanism or an interconnecting network; a complex whole

the state railway system

fluid is pushed through a system of pipes or channels

a set of principles or procedures according to which something is done; an organized scheme or method

a multiparty system of government

the public school system

the prevailing political or social order, especially when regarded as oppressive and intransigent

don't try bucking the system

a set of staves in a musical score joined by a brace