Definition of alligator weed
: a prolific herbaceous weed (Alternanthera phylloxeroides) having opposite entire linear-lanceolate leaves and flowers in short headlike spikes and being especially troublesome in irrigation canals and waterways which it clogs with a dense floating mass
Love words? You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.
Start your free trial today and get unlimited access to America's largest dictionary, with:
- More than 250,000 words that aren't in our free dictionary
- Expanded definitions, etymologies, and usage notes
- Advanced search features
- Ad free!
Origin and Etymology of alligator weed
so called from its long narrow leaves
First Known Use: 1887
Seen and Heard
What made you want to look up alligator weed? Please tell us where you read or heard it (including the quote, if possible).