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

But, there are also some unnecessary (potentially irritating) extras—eucalyptus oil, parfum, and benzyl alcohol. —Boutayna Chokrane, Wired News, 24 June 2025

Inés smelled eucalyptus and aloe in addition to an herbaceous basil and peppery tomato. —Sam Stone, Bon Appetit Magazine, 24 June 2025

The brand’s Breeze duvet cover features an extra-soft, 300 single-ply thread count sateen weave fabric made from Tencel eucalyptus lyocell fibers, which helps absorb moisture and promote a restful sleep. —Jacorey Moon, Architectural Digest, 21 June 2025

It’s made with a blend of alpaca fiber and Tencel from eucalyptus, adding softness, warmth, and excellent moisture-wicking capabilities. —Kevin Brouillard, Travel + Leisure, 19 June 2025

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