eucalyptus

noun

eu·​ca·​lyp·​tus ˌyü-kə-ˈlip-təs 

plural eucalypti ˌyü-kə-ˈlip-ˌtī  -ˌtē  or eucalyptuses

: any of a genus (Eucalyptus) of mostly Australian evergreen trees or rarely shrubs of the myrtle family that have rigid entire leaves and umbellate flowers and are widely cultivated for their gums, resins, oils, and woods

Examples of eucalyptus in a Sentence

Recent Examples on the Web

The wreath is made up of an assortment of beautiful blue wildflowers and daisies that are supported by green eucalyptus leaves with sprinkles of white daisies for extra depth. —Alicia Geigel, Southern Living, 3 Apr. 2026

Allbirds spent lavishly on ad campaigns aimed at pushing new iterations of its signature wool shoes and touting sneakers made of materials like eucalyptus-tree-fiber pulp. —Phil Wahba, Fortune, 1 Apr. 2026

The company, which makes shoes from wool and eucalyptus, attracted young Bay Area consumers and celebrities for its sustainable practices, but has since struggled to find its footing. —Itzel Luna, Los Angeles Times, 1 Apr. 2026

This material is a derivative of eucalyptus with moisture absorption properties to wick away sweat from skin. —Julia Harrison, Architectural Digest, 30 Mar. 2026

Word History

Etymology

borrowed from New Latin, genus name, from Greek eu- eu- + kalyptós "covered," verbal adjective of kalýptein "to cover, protect, conceal"; so named for the operculum that covers the developing buds — more at apocalypse

Note: The genus name was introduced by the French botanist Charles Louis L'Héritier de Brutelle (1746-1800) in Sertum Anglicum, seu Plantae rariores quæ in hortis juxta Londinum, imprimis in Horto Regio Kewensi excoluntur (London, 1788), p. 11. According to E.V. Slee et al., EUCLID: Eucalypts of Australia, 3rd edition (online publication), the specimen of Eucalyptus obliqua which L'Héritier described in Kew Gardens had been procured in 1777 by the botanical collector David Nelson at Adventure Bay, Bruny Island, Tasmania, on James Cook's third voyage to the Pacific.

First Known Use

1801, in the meaning defined above

Kids Definition

eucalyptus

noun

eu·​ca·​lyp·​tus ˌyü-kə-ˈlip-təs 

plural eucalypti -ˌtī 

-ˌtē

or eucalyptuses

: any of a genus of mostly Australian evergreen trees of the myrtle family including many that are widely cultivated for their gums, resins, oils, and useful woods

Medical Definition

eucalyptus

noun

eu·​ca·​lyp·​tus ˌyü-kə-ˈlip-təs 

1

capitalized : a genus of mostly Australian evergreen trees or rarely shrubs of the myrtle family that have rigid entire leaves and umbellate flowers and are widely cultivated for their gums, resins, oils, and useful woods

2

plural eucalypti -ˌtī  -ˌtē  or eucalyptuses : any tree or shrub of the genus Eucalyptus

eucalyptus adjective