phylum

American  

[fahy-luhm] / ˈfaɪ ləm /

noun

plural

phyla

1. Biology. the primary subdivision of a taxonomic kingdom, grouping together all classes of organisms that have the same body plan.

2. Linguistics. a category consisting of language stocks that, because of cognates in vocabulary, are considered likely to be related by common origin.

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phylum British  

/ ˈfaɪləm /

noun

1. a major taxonomic division of living organisms that contain one or more classes. An example is the phylum Arthropoda (insects, crustaceans, arachnids, etc, and myriapods)

2. any analogous group, such as a group of related language families or linguistic stocks

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phylum Scientific  

/ fī′ləm /

plural

phyla

1. A group of organisms ranking above a class and below a kingdom.

2. See Table at taxonomy

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phylum Cultural  

1. plur. phyla One of the major divisions of the kingdoms of living things; the second-largest standard unit of biological classification. The arthropods, chordates, and mollusks are phyla. Phyla in the plant kingdom are frequently called divisions. (See Linnean classification.)

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Other Word Forms

• phylar adjective

Etymology

Origin of phylum

1875–80; < New Latin < Greek phŷlon tribe, stock; phylon

Explanation

If someone asks you what you have in common with the Antarctic icefish, you can say that you both belong to the same phylum, meaning the same taxonomic group: you are both vertebrates. Biology types are probably already familiar with using the word phylum as a way to classify animals and plants. Mammals, including humans, are part of the phylum chordata, which also includes fishes, amphibians, reptiles, and birds. As you can see that’s a very broad category. Phylum comes above class and below kingdom in the biological classification system. The ranks get increasingly narrow, working all the way down to species, which is a closely related group.

Example Sentences

Crinoids are part of the phylum Echinodermata which also boasts sea urchins and sea cucumbers.

From BBC • Feb. 19, 2026

Scientists have identified more than 250,000 species so far, making them the most numerous animal phylum in both land and water ecosystems.

From Science Daily • Jan. 10, 2026

Scientists have known for some time that animals in the phylum Cnidaria—which includes jellyfish, corals, and sea anemones—are capable of basic forms of learning when repeatedly presented with a stimulus in their environment.

From Science Magazine • Sep. 22, 2023

However, Moysiuk says these might have been comb jellies from the Ctenophora phylum, rather than the Cnidaria phylum which includes jellyfish, corals and sea anemones.

From Salon • Aug. 2, 2023

The most populous phylum in our locker room, the Kilt Pins took up three rows of lockers.

From "Middlesex: A Novel" by Jeffrey Eugenides