sub·​unit ˈsəb-ˌyü-nət How to pronounce subunit (audio)
variants or less commonly sub-unit
plural subunits also sub-units
: a unit that is part of a larger unit : a subdivision of a unit
In the U.S. Army's case … the smallest subunit is the squad (nine to twelve individuals under a sergeant).Norman Friedman
Because of a quirk in the replicative machinery, when a strand of DNA is duplicated during mitosis, a few subunits at one end are always lost.John Rennie

Examples of subunit in a Sentence

Recent Examples on the Web Integral to the design of new facades were synthetic polymers: materials made of chains of repeating subunits, and which are the main ingredient of household plastics. Alex Christian, WIRED, 1 Mar. 2024 Unlike traditional vaccines, which rely on injecting a dose of the entire disabled or weakened virus, scientists developing protein subunit vaccines pick out only specific fragments of the virus to trigger an immune response. Alexander Tin, CBS News, 1 Feb. 2022 Polymers are formed by chemical reactions among subunits called monomers, which can link up to create a gel like the type used in gummy candies. Elizabeth Rayne, Ars Technica, 8 June 2023 Shionogi also recently applied for approval to market a protein subunit COVID-19 vaccine. Bydennis Normile,, 9 Feb. 2023 Scaling a battery from a subunit of a single cell to a full cell and eventually to a full battery pack can create a lot of problems, says Srinivasan. Daniel Oberhaus, Wired, 8 Dec. 2020 Explore See latest videos, charts and news The album contains 10 tracks, all of which feature different combinations of the members across group subunits. Starr Bowenbank, Billboard, 28 Aug. 2023 The idea is that, once emplaced, a Littoral Regiment can scatter smaller subunits armed with sensors, anti-ship missiles, and air-defense missiles throughout an area. Kyle Mizokami, Popular Mechanics, 6 July 2023 Moreover, the subunits of the battle groups had to come from and be paid for by EU member states, which led to shirking, particularly by smaller countries. Radek Sikorski, Foreign Affairs, 20 June 2023

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'subunit.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1852, in the meaning defined above

Time Traveler
The first known use of subunit was in 1852

Dictionary Entries Near subunit

Cite this Entry

“Subunit.” Dictionary, Merriam-Webster, Accessed 25 May. 2024.

Kids Definition


: a unit that forms an individually distinct part of a more comprehensive unit

Medical Definition


sub·​unit ˈsəb-ˌyü-nət How to pronounce subunit (audio)
: a unit that forms a discrete part of a more comprehensive unit
subunits of a protein
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!