ragweed

definition: any of numerous chiefly North American weedy plants constituting the genus Ambrosia that produce highly allergenic pollen responsible for much hay fever and asthma
example:
speech part: noun
synonyms: ambrosia
definition: widespread European weed having yellow daisylike flowers
example:
speech part: noun
synonyms: ragwort tansy ragwort benweed

How ragweed is being used?