alga

noun

al·ga ˈal-gə

plural algae ˈal-(ˌ)jē

also algas

: a plant or plantlike organism of any of several phyla, divisions, or classes of chiefly aquatic usually chlorophyll-containing nonvascular organisms of polyphyletic origin that usually include the green, yellow-green, brown, and red algae in the eukaryotes and especially formerly the cyanobacteria in the prokaryotes

algal

ˈal-gəl

adjective

Example Sentences

Recent Examples on the Web Namely, a safe place to hide from predators and a source of food in the form of small, single-celled alga that grow on red seaweed plants, reports Erik Stokstad for Science.

Sarah Kuta, Smithsonian Magazine, 29 July 2022 Giant kelp is the common name for Macrocystis pyrifera, a species of alga that grows into lush underwater forests along the coast of the northeastern Pacific Ocean, from Baja California north to southeastern Alaska.

Andrew Robinson, Scientific American, 21 July 2022 Lichens are actually two organisms working together: a fungus and either alga or cyanobacterium.

Corryn Wetzel, Smithsonian Magazine, 17 Feb. 2022 The lagoons are home to a variety of microorganisms, including Dunaliella salina, an alga responsible for the red hue.

Washington Post, 10 Dec. 2021 This alga is a critical food source for brine shrimp and other salt-tolerant species, which attract migratory shorebirds.

Washington Post, 10 Dec. 2021 The course, woolly textured alga was found in a portion of the Upper Manistee River in Kalkaska County.

Keith Matheny, Detroit Free Press, 7 Dec. 2021 The secret to photosynthesis passed to the alga and all its heirs.

Elizabeth Kolbert, The New Yorker, 6 Dec. 2021 Yet the verdant spheres are a different organism altogether: Chlorella, an alga that occasionally takes refuge within the confines of the paramecium’s cushy cell membrane.

Quanta Magazine, 7 June 2021 See More

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

Word History

Etymology

Latin, seaweed

First Known Use

1551, in the meaning defined above

Time Traveler

The first known use of alga was in 1551

See more words from the same year

Cite this Entry

Style

“Alga.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/alga. Accessed 7 Dec. 2022.

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