li·​chen | \ ˈlī-kən How to pronounce lichen (audio) , British also ˈli-chən \

Definition of lichen

1 : any of numerous complex plantlike organisms made up of an alga or a cyanobacterium and a fungus growing in symbiotic association on a solid surface (such as on a rock or the bark of trees)

Note: The main body of the lichen, known as the thallus, is formed by fungal filaments which surround the photosynthetic algal or cyanobacterial cells. The lichen is usually described as having a leaflike (foliose), crusty (crustose), or branching shrub-like (fruticose) form. Lichens often play an important part in the weathering of rocks and include some that are sources of natural dyes.

2 : any of several skin diseases characterized by the eruptions of flat papules

Illustration of lichen

Illustration of lichen

lichen 1

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Other Words from lichen

lichened \ ˈlī-​kənd How to pronounce lichened (audio) , British also  ˈli-​chənd \ adjective
lichenous \ ˈlī-​kə-​nəs How to pronounce lichenous (audio) , British also  ˈli-​chə-​ \ adjective

Examples of lichen in a Sentence

Recent Examples on the Web There, ox-eye daisies flourish from portentous box tombs, and the stone is softened by gold lichen; once-grieving cherubs wink from garlands of ivy, and extravagant calligraphy is worn to flourishes and flowers. 1843, "Can words do the dead justice?," 21 May 2020 Canada has among the highest lichen biomass in the world, competing only with Russia. Sara Miller Llana, The Christian Science Monitor, "Heads up, maple leaf. Canada’s eyeing another national icon.," 31 Mar. 2020 The relationship in the NASA myco-architectural model resembles naturally occurring lichen, which are composite organisms made of cyanobacteria and different kinds of fungi. Caroline Delbert, Popular Mechanics, "We're All Going to Live in Mushroom Houses on Mars," 16 Jan. 2020 The hummingbird was building herself a nest, one lichen chip and strand of spider silk at a time. Jonah Weiner, New York Times, "How Watching Bald Eagles Build a Nest Prepared Me for the Pandemic," 12 May 2020 The above-zero temperatures that contribute to Antarctic melting could likely lead to flooding and more mosses, lichens, microbes and invertebrates. Cailey Rizzo, Travel + Leisure, "This Antarctica Research Base Recorded Their Hottest Summer Ever," 1 Apr. 2020 Hutchins drew her discoveries, which included the lichen Lecania hutchinsiae, one of many species named in her honor. George Lin, National Geographic, "5 surprising ways to celebrate gardens this spring," 18 Feb. 2020 The unkempt grass alleys and neglected ranks of markers, their stone casings mottled with moss and lichen, speak to the lost world of Jews here. Adam Nossiter, New York Times, "Jewish Cemeteries Are Threatened. These People Are Guarding Them.," 5 Mar. 2020 The case for choosing a Canadian lichen is compelling. The Economist, "A little lichen relief Canada’s quest for a national lichen," 19 Mar. 2020

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

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First Known Use of lichen

circa 1657, in the meaning defined at sense 2

History and Etymology for lichen

Latin, from Greek leichēn, lichēn, from leichein to lick

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Time Traveler for lichen

Time Traveler

The first known use of lichen was circa 1657

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Statistics for lichen

Last Updated

29 May 2020

Cite this Entry

“Lichen.” Dictionary, Merriam-Webster, Accessed 7 Jun. 2020.

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More Definitions for lichen


How to pronounce lichen (audio)

English Language Learners Definition of lichen

: a type of small plant that grows on rocks and walls


li·​chen | \ ˈlī-kən How to pronounce lichen (audio) \

Kids Definition of lichen

: a plantlike organism made up of an alga and a fungus growing together


li·​chen | \ ˈlī-kən How to pronounce lichen (audio) \

Medical Definition of lichen

1 : any of several skin diseases characterized by the eruption of flat papules especially : lichen planus
2 : any of numerous complex plantlike organisms made up of an alga and a fungus growing in symbiotic association on a solid surface (as a rock)

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More from Merriam-Webster on lichen

Rhyming Dictionary: Words that rhyme with lichen

Spanish Central: Translation of lichen

Nglish: Translation of lichen for Spanish Speakers Encyclopedia article about lichen

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