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

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 31 Jan. 2023.

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
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