ragweed

The story

1. Englishragwort
2. Proto-West Germanic*weud
3. Old Englishwēod
4. Middle Englishweed
5. Englishweed
6. English todayragweed

Alteration of earlier ragwort; presumably equivalent to ragged + weed, with "rag" referring to the tattered appearance of the plant's leaves. Compare Middle English ragwed (“butcher's broom”), of uncertain linguistic relationship.

First known use, by meaning

• 1790 A plant of the genus Ambrosia, native to North America and a common invasive species elsewhere, particularly noted for producing pollen that triggers hay fever.
• 1610 Synonym of ragwort.