alligator weed

variants: or alligator grass

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!

First Known Use of alligator weed

1887, in the meaning defined above

History and Etymology for alligator weed

so called from its long narrow leaves

Learn More About alligator weed

Time Traveler for alligator weed

Time Traveler

The first known use of alligator weed was in 1887

See more words from the same year

Dictionary Entries Near alligator weed

alligator tree

alligator weed


See More Nearby Entries 

Statistics for alligator weed

Cite this Entry

“Alligator weed.” Dictionary, Merriam-Webster, Accessed 29 Nov. 2021.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon


Test Your Vocabulary

Difficult Spelling Words Quiz

  • alphabet pasta spelling help
  • Which is the correct spelling?
True or False

Test your knowledge - and maybe learn something along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!