multicellular
adjective
mul·ti·cel·lu·lar
ˌməl-tē-ˈsel-yə-lər 
-ˌtī-
: having, made up of, or involving more than one and usually many cells especially of living matter
It is probable that with a few exceptions all the cells in a multicellular organism have the same genetic information encoded in the chains of nucleotide bases that make up their DNA.—
James E. Darnell, Jr.
James E. Darnell, Jr.A biofilm is a community of bacteria that use intercellular signaling to establish complex multicellular structures by coordinating gene expression and phenotypic changes.—J. Christopher Post et al.
J. Christopher Post et al.
multicellularity
noun
When is an organism multicellular? A generic answer … is that multicellularity results when two or more neighboring cells adhere, interact, and physiologically communicate.
—Karl J. Niklas
Karl J. Niklas
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Multicellular organisms are distinguished from the very primitive single-celled organisms—bacteria, algae, amoebas, etc. Even sponges, simple as they are, have specialized cell types such as digestive cells. In complex multicellular organisms, only the surface cells can exchange substances with the external environment, so the organisms have developed transport systems such as the circulatory system, in which the blood brings gases and nutrients to the cells and removes waste products from them.
Examples of multicellular in a Sentence
Recent Examples on the Web
Known as the Sponge Capital of the World, the area’s major commodity is the super-absorbent multicellular organism that’s found on the ocean floor.
—Tara Massouleh McCay, Southern Living, 2 July 2025
The empty oceans provided new habitats and opportunities for the survivors, and eukaryotic microbes experienced a significant boost in their evolution, leading to the emergence of complex, multicellular organisms over the next 100 million years.
—David Bressan, Forbes.com, 20 June 2025
Then there was the transition to multicellular organisms (around 2 billion to 1.6 billion years ago), the abrupt diversification of body forms in the Cambrian explosion (540 million years ago), and the appearance of central nervous systems (around 600 million to 520 million years ago).
—Philip Ball, Wired News, 8 June 2025
Another study asked why bacteria and other prokaryotic cells failed to evolve into complex multicellular life.
—Quanta Magazine, 18 Dec. 2024
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Tara Massouleh McCay, Southern Living, 2 July 2025
The empty oceans provided new habitats and opportunities for the survivors, and eukaryotic microbes experienced a significant boost in their evolution, leading to the emergence of complex, multicellular organisms over the next 100 million years.
—David Bressan, Forbes.com, 20 June 2025
Then there was the transition to multicellular organisms (around 2 billion to 1.6 billion years ago), the abrupt diversification of body forms in the Cambrian explosion (540 million years ago), and the appearance of central nervous systems (around 600 million to 520 million years ago).
—Philip Ball, Wired News, 8 June 2025
Another study asked why bacteria and other prokaryotic cells failed to evolve into complex multicellular life.
—Quanta Magazine, 18 Dec. 2024
See All Example Sentences for multicellular
Cite this Entry
“Multicellular.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/multicellular. Accessed 26 Jul. 2025.
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