unicellular

adjective

uni·​cel·​lu·​lar ˌyü-ni-ˈsel-yə-lər 

: having or consisting of a single cell

unicellular microorganisms

Examples of unicellular in a Sentence

Recent Examples on the Web

But in any case, one question then is how does a unicellular organism manage to make this transition, in any of these cases? —Steven Strogatz, Quanta Magazine, 20 Mar. 2025

This would mean that the transition from unicellular to multicellular life was not a leap requiring entirely new genes but rather an evolutionary refinement of existing genetic mechanisms. —Scott Travers, Forbes, 11 Dec. 2024

There are lots of other things in between them — things that branched off the lineage leading to plants and things that branched off the lineage leading to animals — that are mostly unicellular organisms. —Janna Levin, Quanta Magazine, 24 Oct. 2024

As a result, populations of unicellular organisms spiked. —Eric Lagatta, USA TODAY, 23 Oct. 2024

Word History

First Known Use

1858, in the meaning defined above

Rhymes for unicellular

• extracellular
• intercellular
• intracellular
• multicellular
• acellular
• subcellular
• cellular
• hepatocellular

Kids Definition

unicellular

adjective

uni·​cel·​lu·​lar ˌyü-ni-ˈsel-yə-lər 

: having or consisting of a single cell

unicellular microorganisms

Medical Definition

unicellular

adjective

uni·​cel·​lu·​lar ˌyü-ni-ˈsel-yə-lər 

: having or consisting of a single cell

unicellular microorganisms

unicellularity

-ˌsel-yə-ˈlar-ət-ē 

noun

plural unicellularities