apparatus

noun

ap·​pa·​ra·​tus ˌa-pə-ˈra-təs  -ˈrā- 

plural apparatuses or apparatus

1

a

: a set of materials or equipment designed for a particular use

b

: a group of anatomical or cytological parts functioning together

mitotic apparatus

c

: an instrument or appliance designed for a specific operation

an apparatus for measuring vision

2

: the functional processes by means of which a systematized activity is carried out

the apparatus of society

: such as

a

: the machinery of government

b

: the organization of a political party or an underground movement

Synonyms of apparatus

• equipment
• gear

Examples of apparatus in a Sentence

Recent Examples on the Web

Her government has since been navigating a delicate transition, balancing pressure from Washington for cooperation on corruption and criminal cases with the demands of powerful figures within Venezuela’s military and security apparatus who remain wary of the rapidly shifting political landscape. —Antonio María Delgado, Miami Herald, 7 Mar. 2026

Experts are gaming out scenarios in which civilian protests reach a critical mass and one or more branches of the security apparatus—the Revolutionary Guard, the Basij militia, the regular army—break away from the regime. —Bobby Ghosh, Time, 5 Mar. 2026

The two-time first-team All-American on beam has been named Big Ten event specialist of the week three times this season for her high performances on multiple apparatuses. —Anthony Solorzano, Los Angeles Times, 5 Mar. 2026

Her willingness to meet with CIA Director John Ratcliffe for a two-hour summit in Caracas underscored her authority to pivot the entire state apparatus toward a new energy partnership with the West. —Karim Sadjadpour, The Atlantic, 4 Mar. 2026

Word History

Etymology

borrowed from Latin apparātus "act of preparing, display, trappings, equipment," from apparāre "to make ready, make preparations for" (from ad- ad- + parāre "to supply, provide, make ready") + -tus, suffix of verbal nouns — more at pare

First Known Use

circa 1628, in the meaning defined at sense 1a

Phrases Containing apparatus

• Golgi apparatus

Rhymes for apparatus

• superlattice
• beatus
• flatus
• gratis
• lattice
• rattus
• satis
• status
• stratus

Kids Definition

apparatus

noun

ap·​pa·​ra·​tus ˌap-ə-ˈrat-əs  -ˈrāt- 

plural apparatuses or apparatus

1

: the equipment or material for a particular use or job

laboratory apparatus

2

: a complicated instrument or device

Medical Definition

apparatus

noun

ap·​pa·​ra·​tus ˌap-ə-ˈrat-əs  -ˈrāt- 

plural apparatuses or apparatus

: a group of anatomical and cytological parts having a common function

the respiratory apparatus

see golgi apparatus