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

Pritt also recommends using 30% DEET or oil of lemon eucalyptus bug repellent. —Kaitlin Sullivan, NBC news, 4 June 2026

The ones that pass the test, such as DEET, picaridin and oil of lemon eucalyptus, are clinically proven effective. —Bestreviews, Mercury News, 3 June 2026

The island’s botanical gardens are filled with palms, cacti, eucalyptus trees, and other Mediterranean flora. —Brittany Anas, Forbes.com, 1 June 2026

Their body care kit gets to the root of smooth skin with a trio of products including a pre-sluff bar that rids it of lotions and oils, a washable textured mitt that sloughs off dead cells and a eucalyptus-scented body lotion that loads it with hydration while making your bathroom smell like a spa. —Jackie Fields, PEOPLE, 1 June 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