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

And the staff handles that amid the backdrop of a kinetic healthcare delivery apparatus. — Richard Menger Md Mpa, Forbes.com, 15 Aug. 2026

The Muon g-2 apparatus uses a 50-foot-diameter superconducting storage ring to hold positive muons — technically anti-muons — traveling at nearly the speed of light. — Rupendra Brahambhatt, Interesting Engineering, 15 Aug. 2026

Scientists have also found giant squid beaks (its biting apparatus) in sperm whale stomachs. — Laura Baisas, Popular Science, 13 Aug. 2026

The teen was using an apparatus called a third lung, which floats on the water's surface and pumps air to divers through a breathing hose, the affidavit said. — Bill Hutchinson, ABC News, 7 Aug. 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