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

The reward targets Mojtaba Khamenei, the son of Iran’s late Supreme Leader Ayatollah Ali Khamenei, along with several key figures inside Iran’s ruling security apparatus. —Michael Dorgan , Greg Norman-Diamond, FOXNews.com, 14 Mar. 2026

Neuroplastogens would fit much more comfortably in the existing apparatus for drug development, regulation, and distribution, without the cultural baggage. —Clayton Dalton, New Yorker, 13 Mar. 2026

The result is a federal budgeting apparatus that, through an accumulation of outdated rules and political compromises, consistently produces rosier projections than reality warrants. —Nick Lichtenberg, Fortune, 13 Mar. 2026

And one of the fun parts was to see the entire apparatus around the movie scramble to clear a Harry Styles song in 36 hours. —Aaron Couch, HollywoodReporter, 12 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