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

• equipment
• gear

Examples of apparatus in a Sentence

Recent Examples on the Web

The apparatus is an automatic closed system that incorporates a fermentation vat and a centrifuge to simulate lunar gravity. —David Szondy october 19, New Atlas, 19 Oct. 2025

Within three years, and after making a significant investment in its publicity apparatus (hiring ace awards strategist Lisa Taback), Netflix received its first Academy Award nomination for Best Picture, Alfonso Cuarón’s Roma. —Joe Reid, Vulture, 17 Oct. 2025

The injury took place when an apparatus used by athletes to attach warmup bands to instruments malfunctioned, according to an ESPN report. —Skyler Caruso, PEOPLE, 14 Oct. 2025

Nelson, an accomplished heart surgeon who performed Utah's first open-heart surgery in 1955 and helped develop an artificial heart and lung apparatus, became a full-time church leader in 1984. —Marc Ramirez, USA Today, 14 Oct. 2025

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