ageratum

noun ag·er·a·tum \ ˌa-jə-ˈrā-təm \
Updated on: 5 Apr 2018

Definition of ageratum

plural ageratum also ageratums
: any of a genus (Ageratum) of annual tropical American composite herbs often cultivated for their small showy heads of usually blue or white flowers; also : a related blue-flowered perennial (Eupatorium coelestinum)

Recent Examples of ageratum from the Web

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

Origin and Etymology of ageratum

borrowed from New Latin (Linnaeus), going back to Latin ageraton (Pliny), a plant, perhaps Achillea ageratum, borrowed from Greek agḗraton (Dioscorides), from neuter of agḗratos "ageless, undecaying," from a- 2a- + -gēratos, derivative from the base of gêras "old age" — more at geront-
Note: Introduced by Linnaeus in Hortus Cliffortianus (Amsterdam, 1737), p. 396. The name may have been suggested to Linnaeus by the resemblance of his Ageratum conyzoides to some species of Eupatorium, which, in pre-Linnaean nomenclature, were also called Ageratum; specifically, the plant now known as Achillea ageratum, which may have been the ancients' ageraton, was called by herbalists both Ageratum and Eupatorium mesues (e.g., in Joseph Miller's Botanicum officinale, or a Compendious Herbal, London, 1722, p. 18). In Genera Plantarum, 2. ed. (p. 392), Linnaeus notes that he departs from previous application of the name ("Aliud est Ageratum Boerhaavii, quod partim ad Achillæas, partim ad Tanaceta spectat"). In Dioscorides' account of the plant in Greek, agḗraton is so called because the flowers keep their form for a long time.


Learn More about ageratum


Seen and Heard

What made you want to look up ageratum? Please tell us where you read or heard it (including the quote, if possible).

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

WORD OF THE DAY

of the same or a similar kind or nature

Get Word of the Day daily email!

Test Your Vocabulary

May 2018 Words of the Day Quiz

  • spring-flowers
  • Which is a synonym of raillery?
Name That Thing

Test your visual vocabulary with our 10-question challenge!

TAKE THE QUIZ
Dictionary Devil

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!