bastard feverfew

noun

: a tropical American annual weed (Parthenium hysterophorus) with small radiate heads of white flowers that is adventive in the southern U.S.

The Ultimate Dictionary Awaits

Expand your vocabulary and dive deeper into language with Merriam-Webster Unabridged.

1. Expanded definitions
2. Detailed etymologies
3. Advanced search tools
4. All ad-free

Discover what makes Merriam-Webster Unabridged the essential choice for true word lovers.

Start Your Free Trial Now