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

In the adjacent dining area, furniture-like cabinetry wraps a corner, and Shaker-style chairs stained lichen green surround a farmhouse table made from salvaged pine. Marni Elyse Katz,, "A Maine lake house gives three generations both togetherness and privacy," 20 June 2019 These crusts have moss, glycogen, lichen and cyanobacteria, all compounds that act as a natural glue that make the soil moister and more stable and add vital microbes that give loose soil some structural stability., "Summer storms are a spectacle, but the dust in them is hazardous to your health," 18 June 2019 The girls scattered, gathering wood and old-man’s beard, a pale-green lichen that makes a good fire starter. Susan Shain, The Atlantic, "When Your Final Exam Is Surviving the Wilderness," 5 June 2019 There are varieties of random paths, random two-dimensional surfaces, random growth models that approximate, for example, the way a lichen spreads on a rock. Quanta Magazine, "A Unified Theory of Randomness," 2 Aug. 2016 Incorporate things like moss, lichen-covered sticks or river stones to add more visual interest while still keeping the look natural. Emma Bazilian, House Beautiful, "This Super-Easy 'Living Arrangement' Takes Container Gardening to the Next Level," 26 Apr. 2019 The little guests were able to take turns feeding the animals handfuls of lichen. Chloe Foussianes, Town & Country, "Duchess Camilla Gets into the Christmas Spirit, Hangs Out with a Couple Reindeer," 7 Dec. 2018 The toughest Earth creature could be the water bear, or tardigrades, which are .04 inch long invertebrate animals that live in mosses, soil, or lichens on earth. Joe Pappalardo, Popular Mechanics, "What Would Life on Mars Be Like?," 25 July 2018 The blues even have a little bit of a green undertone, like lichen on a stone. Lisa Cregan, House Beautiful, "Susan Ferrier on Creating a Cozy Lake House With Dark Colors," 18 Aug. 2014

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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Dictionary Entries near lichen


lich bird





lichen green

Statistics for lichen

Last Updated

27 Jun 2019

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Time Traveler for lichen

The first known use of lichen was circa 1657

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More Definitions for lichen



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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