Definition of peridinium
1 capitalized : the type genus of Peridiniidae comprising marine and freshwater dinoflagellates that are typically subspherical to ovoid in outline and that sometimes have the test prolonged into short horns — compare ceratium
2 plural peridiniums \-ēəmz\ or peridinia \-ēə\ : any flagellate of the genus Peridinium
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!
Seen and Heard
What made you want to look up peridinium? Please tell us where you read or heard it (including the quote, if possible).