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

Operated by Heartland Fire and Rescue, the station is located in Fletcher Hills and was constructed in 1960 with a single apparatus bay and a shared dormitory. —Hannah Elsmore, San Diego Union-Tribune, 27 Mar. 2026

Mullin inherits a rapidly expanding immigration-enforcement apparatus at DHS, amped up by $170 billion in additional funding. —Nick Miroff, The Atlantic, 27 Mar. 2026

The launch apparatus uses a battery operations center and transporter erector launcher, sending the missile streaking east over the Atlantic. —Richard Tribou, The Orlando Sentinel, 26 Mar. 2026

The city's police force is understaffed and its public safety apparatus is inadequate to deliver justice, with too little jail space and too few prosecutors and judges to move cases through the courts. —Cleve R. Wootson Jr. The Washington Post, Arkansas Online, 25 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