Pronunciation: ' bi-t ə r- ˌ w ē d
Function: noun
Date: 1819
: any of several American plants containing a bitter substance: as a : either of two ragweeds: (1) : a low-growing common ragweed ( Ambrosia artemissiifolia ) (2) : HORSEWEED b : an annual yellow-flowered sneezeweed ( Helenium amarum syn. H. tenuifolium ) c : an erect annual composite herb ( Hymenoxys odorata ) of the southwestern U.S. that has yellow flowers and is poisonous to livestock