algae

[ al-jee ]

/ ˈæl dʒi /

SEE MORE SYNONYMS FOR algae ON THESAURUS.COM

plural noun, singular al·ga [al-guh] /ˈæl gə/.

any of numerous groups of chlorophyll-containing, mainly aquatic eukaryotic organisms ranging from microscopic single-celled forms to multicellular forms 100 feet (30 meters) or more long, distinguished from plants by the absence of true roots, stems, and leaves and by a lack of nonreproductive cells in the reproductive structures: classified into the six phyla Euglenophyta, Crysophyta, Pyrrophyta, Chlorophyta, Phaeophyta, and Rhodophyta.

RELATED WORDS

seaweed, scum, dulse, kelp

Nearby words

alfvén, alfvén wave, alföld, alg., alga, algae, algal, algar, algaroth powder, algarroba, algarve

Compare blue-green algae.

Origin of algae

< New Latin, plural of Latin alga seaweed

Related formsal·gal, adjective

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for algae

We would have considered an algae bloom to be a welcome sign of ecological renewal.
Toledo: The Town Too Tough for Toxic Water|P. J. O’Rourke|August 4, 2014|DAILY BEAST
Algae, sponges and coral now cover nuns, small children, and the elderly upper class.
Artist Jason deCaires Taylor’s Underwater Sculptures Are a Sight to Sea|Justin Jones|April 7, 2014|DAILY BEAST
Glowing bacteria might live in our ceilings and light our homes, while algae bioreactors could supply food and fuel.
It’s the End of the World but We’ll Be Fine|Nick Romeo|May 18, 2013|DAILY BEAST
Newt Gingrich has been scoring points ridiculing the idea of algae as a fuel of the future.
Gas from Algae? Hilarious!|David Frum|March 16, 2012|DAILY BEAST

The rainbow of life in a coral reef is founded on the partnership between polyps and algae.
Here on Earth, The Forgotten Founding Father, and Other Reviews|The Daily Beast|April 30, 2011|DAILY BEAST
Against the walls Tom could see the great hydroponic vats that held the yeast and algae cultures that fed the crew of the ship.
Gold in the Sky|Alan Edward Nourse
The gas is sometimes withdrawn and the deposit produced in large part by the action of algae and other humble forms of plant life.
The Elements of Geology|William Harmon Norton
He regarded a bowl of algae as if about to make it disappear.
Greener Than You Think|Ward Moore
Solomon in all his glory had nothing on the algae; and the Queen of Sheba nothing on Cynthy.
Maw's Vacation|Emerson Hough
An aerator is used before filtration during the summer, when algae are likely to develop in the reservoir.
Transactions of the American Society of Civil Engineers, vol. LXXII, June, 1911|E. D. Hardy

British Dictionary definitions for algae

algae

/ (ˈældʒiː) /

pl n singular alga (ˈælɡə)

unicellular or multicellular organisms formerly classified as plants, occurring in fresh or salt water or moist ground, that have chlorophyll and other pigments but lack true stems, roots, and leaves. Algae, which are now regarded as protoctists, include the seaweeds, diatoms, and spirogyra

Derived Formsalgal (ˈælɡəl), adjective

Word Origin for algae

C16: from Latin, plural of alga seaweed, of uncertain origin

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for algae

algae

(plural), 1794, from alga (singular), 1550s, from Latin alga "seaweed," of uncertain origin, perhaps from a PIE root meaning "to putrefy, rot."

Medicine definitions for algae

algae

[ ăl′jē ]

pl.n.

Any of various chiefly aquatic, eukaryotic, photosynthetic organisms, ranging in size from single-celled forms to the giant kelp.

Science definitions for algae

alga

[ ăl′gə ]

Plural algae (ăl′jē)

Any of various green, red, or brown organisms that grow mostly in water, ranging in size from single cells to large spreading seaweeds. Like plants, algae manufacture their own food through photosynthesis and release large amounts of oxygen into the atmosphere. They also fix large amounts of carbon, which would otherwise exist in the atmosphere as carbon dioxide. Algae form a major component of marine plankton and are often visible as pond scum and blooms in tidal pools. Land species mostly live in moist soil and on tree trunks or rocks. Some species live in extreme environments, such as deserts, hot springs, and glaciers. Although they were once classified as plants, the algae are now considered to be protists, with the exception of the cyanobacteria, formerly called blue-green algae. The algae do not form a distinct phylogenetic group, but the word alga serves as a convenient catch-all term for various photosynthetic protist phyla, including the green algae, brown algae, and red algae.

Culture definitions for algae

algae

[ (al-jee) ]

Primitive organisms that contain chlorophyll but do not have structures, such as xylem and phloem, to transport fluids. Algae sometimes contain only a single cell, and nowadays they are not considered members of the plant kingdom.

Note

The most familiar algae are the greenish scum that collects in still water.

Note

Algae supply a considerable part of the world's oxygen.