any of the composite plants of the genus Ambrosia, the airborne pollen of which is the most prevalent cause of autumnal hay fever, as the common North American species, A. trifida (great ragweed or giant ragweed) and A. artemisiifolia.
any plant of the chiefly North American genus Ambrosia, such as A. artemisiifolia (common ragweed): family Asteraceae (composites). Their green tassel-like flowers produce large amounts of pollen, which causes hay fever Also called ambrosia
1790, from ragged + weed (n.); so called from shape of the leaves. Applied to a different plant (ragwort) from 1650s.
ragweed rag·weed (rāg’wēd’)
Any of various weeds of the genus Ambrosia having small greenish unisexual flower heads and producing abundant pollen that is one of the chief causes of hay fever.
[rag-wurk] /ˈrægˌwɜrk/ noun 1. masonry of thin, undressed rubble.
/ˈræɡˌwɜːm/ noun 1. any polychaete worm of the genus Nereis, living chiefly in burrows in sand or mud and having a flattened body with a row of fleshy parapodia along each side US name clamworm
[rag-wurt, -wawrt] /ˈrægˌwɜrt, -ˌwɔrt/ noun 1. any of various composite plants of the genus Senecio, as S. jacobaea, of the Old World, having yellow flowers and irregularly lobed leaves, or S. aureus (golden ragwort) of North America, also having yellow flowers. /ˈræɡˌwɜːt/ noun 1. any of several plants of the genus Senecio, esp S. jacobaea […]
[rey-hab] /ˈreɪ hæb/ noun 1. a harlot of Jericho who gave shelter to the two agents sent by Joshua to spy on the city. Josh. 2. name of a Biblical monster, from Hebrew rahab, literally “storming, against, impetuous,” from rahabh “he stormed against” (cf. Arabic rahiba “he feared, was alarmed”). insolence; pride, a poetical name […]