red alga

noun

plural red algae also red algas
: any of a division (Rhodophyta) of chiefly marine algae that have predominantly red pigmentation

Example Sentences

Recent Examples on the Web Cryptophytes are the result of a merger between two organisms: a red alga that was engulfed by another unknown eukaryote (an organism with cells that contain enclosed nuclei). Viviane Callier, Smithsonian, 23 Oct. 2019

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

Word History

First Known Use

1834, in the meaning defined above

Time Traveler
The first known use of red alga was in 1834

Dictionary Entries Near red alga

Cite this Entry

“Red alga.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/red%20alga. Accessed 7 Dec. 2022.

Kids Definition

red alga

noun
: any of various algae that usually grow in the ocean and are of reddish color

Medical Definition

red alga

noun
: any of a division (Rhodophyta) of chiefly marine algae that have predominantly red pigmentation
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