1. a common weedy plant with small greenish flowers that produces large amounts of pollen, often causing hay fever and allergies

Examples

• The ragweed in the vacant lot made her sneeze every morning.
• Many people with seasonal allergies are sensitive to ragweed pollen.
• Ragweed typically blooms in late summer and early fall.
• The city sprayed herbicide to control the ragweed growth along the highway.
• His hay fever symptoms worsen when ragweed season begins.
• Farmers often struggle to eliminate ragweed from their fields.