[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

ambrosia trifida
     n : a coarse annual with some leaves deeply and palmately
         3-cleft or 5-cleft syn: great ragweed
see also:
great ragweed 

Ambrosia >> A Words
Ambrosia, definition of term: Ambrosia
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