plural acontia
or acontiums
: one of the free threads continued from the lower ends of the septa of certain actinians, histologically similar to cnidoglandular bands, protruding through the mouth when the animal contracts, and probably defensive

Word History


New Latin, from Greek akontion javelin, diminutive of akont-, akōn

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!

Dictionary Entries Near acontium

Cite this Entry

“Acontium.” Dictionary, Merriam-Webster, Accessed 25 Feb. 2024.

Love words? Need even more definitions?

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