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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.
noun 1. . noun 1. the Great Rebellion, another name for the English Civil War
noun, Astronomy. 1. . noun, Astronomy. 1. a large, usually reddish gaseous vortex on the surface of Jupiter, about 14,000 by 30,000 km, that drifts about slowly as the planet rotates and has been observed for several hundred years. noun 1. a large long-lived oval feature, south of Jupiter’s equator, that is an anticyclonic disturbance […]
- Great renaming
Usenet, history The flag day in 1986 on which all of the non-local groups on the Usenet had their names changed from the net.- format to the current multiple-hierarchies scheme. Used especially in discussing the history of newsgroup names. “The oldest sources group is comp.sources.misc; before the Great Renaming, it was net.sources.” FAQ (http://vrx.net/usenet/history/rename.html). [Jargon […]
noun 1. . noun 1. a tall shrub, Rhododendron maximum, of eastern North America, having rose-pink flowers.