phylum

noun phy·lum \ ˈfī-ləm \

Updated on: 18 Mar 2018

Definition of phylum

plural phyla play \ˈfī-lə\

1 a : a direct line of descent within a group

b : a group that constitutes or has the unity of a phylum; specifically : a primary category in biological taxonomy especially of animals that ranks above the class and below the kingdom — compare division 10

2 : a group of languages related more remotely than those of a family or stock

See phylum defined for English-language learners

See phylum defined for kids

Recent Examples of phylum from the Web

And discovering an organism different enough to warrant its own phylum comes only to a rare few.

— adrienne mason, Smithsonian, "King of The Mud Dragons," 2 Mar. 2018
The pair decided to build a museum dedicated to the phylum of spineless sea creatures.

— amanda arnold, Smithsonian, "Putting Miniature Museums Where You Are Likely To See Them," 21 Dec. 2017
Scientists previously suspected that tardigrades may be closely related to the phylum of arthropods, which includes insects and spiders.

— ben panko, Smithsonian, "Why Are Tardigrades the World’s Hardiest Creature? DNA Offers Clues," 27 July 2017
The phylum has existed for at least 520 million years, through multiple mass extinctions.

— ben panko, Smithsonian, "How to Kill Nature’s Most Indestructible Creature," 14 July 2017
Horsehair worms, part of the taxonomic phylum Nematomorpha, are parasitic worms that resemble long thin strands of hair (hence their nickname).

— ben panko, Smithsonian, "This Jumble of Writhing Sticks Is Actually a Bizarre Parasite," 27 Sep. 2017
Cephalopods, which include octopi, cuttlefish, and squid, belong to the Mollusca phylum, are chiefly identified by their tentacles.

— colin dickey, New Republic, "When Squid Ruled the Earth," 21 Sep. 2017
Tardigrades is its phylum within the Ecdysozoa superphylum, which includes insects, crustaceans, arachnids and more.

— Fox News, "This eight-legged creature could be Earth's sole survivor -- and help search for aliens," 14 July 2017
The phylum has existed for at least 520 million years, through multiple mass extinctions.

— ben panko, Smithsonian, "How to Kill Nature’s Most Indestructible Creature," 14 July 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'phylum.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of phylum

New Latin, from Greek phylon tribe, race — more at phyl-

NEW! Time Traveler

First Known Use: 1868

See Words from the same year

PHYLUM Defined for English Language Learners

phylum

noun

Definition of phylum for English Language Learners

biology : a large group of related animals or plants

PHYLUM Defined for Kids

phylum

noun phy·lum \ ˈfī-ləm \

Definition of phylum for Students

plural phyla \-lə\

: a group of related living things (as animals or plants) that ranks above the class and below the kingdom in scientific classification

Medical Dictionary

phylum

noun phy·lum \ ˈfī-ləm \

medical Definition of phylum

plural phyla play \-lə\

: a major group of animals or in some classifications plants sharing one or more fundamental characteristics that set them apart from all other animals and plants and forming a primary category of the animal or plant kingdom