[1] : The Collaborative International Dictionary of English v.0.48

ragweed \rag"weed`\ ra^g"w=ed`, n. bot.
   a common american composite weed ambrosia artemisiaefolia
   with finely divided leaves; hogweed.
   1913 webster

   great ragweed, a coarse american herb ambrosia trifida,
      with rough three-lobed opposite leaves.
      1913 webster
see also:
ambrosia artemisiaefolia great ragweed ambrosia trifida 

[2] : WordNet (r) 2.0

ragweed
     n 1: widespread european weed having yellow daisylike flowers;
          sometimes an obnoxious weed and toxic to cattle if
          consumed in quantity syn: ragwort, tansy ragwort, benweed,
           senecio jacobaea
     2: any of numerous chiefly north american weedy plants
        constituting the genus ambrosia that produce highly
        allergenic pollen responsible for much hay fever and
        asthma syn: ambrosia, bitterweed
see also:
ragwort tansy ragwort benweed senecio jacobaea ambrosia bitterweed 

Ragweed >> R Words
Ragweed, definition of term: Ragweed
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