any of several plants (genus Ageratum
) of the composite
family with small, thick heads of usually bluish
flowers: widely used as border
plants in gardens
Webster’s New World College Dictionary, 4th Edition. Copyright © 2010 by
Houghton Mifflin Harcourt. All rights reserved.
Word origin of 'ageratum'ModL < Gr agēraton, a kind of plant < agēratos, not growing old < a-, not + gēras, old age