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

• accoutrements
• accouterments
• equipment
• gear
• hardware
• kit [chiefly British]
• material(s)
• matériel
• materiel
• outfit
• paraphernalia
• stuff
• tackle

Examples of apparatus in a Sentence

Recent Examples on the Web

In recent years, the world’s largest military apparatuses—the U.S. Department of Defense and NATO—have added climate change to their war games. —Brett Simpson, The Atlantic, 28 Mar. 2025

But when Buck calls Athena (Angela Bassett) in to say goodbye, Bobby reveals there was a hole in the air supply line of his breathing apparatus. —Patrick Gomez, EW.com, 18 Apr. 2025

San Diego County’s fire department contracts with Cal Fire to staff its fire stations, but the county supplies and owns the apparatus. —Teri Figueroa, San Diego Union-Tribune, 13 Apr. 2025

The lab's coffee-making apparatuses include an espresso machine, a French press and a pour-over setup. —Elizabeth Weise, USA Today, 8 Apr. 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