actinia

noun

ac·​tin·​ia

ak-ˈti-nē-ə

1

capitalized in some classifications : a genus of sea anemones nearly coextensive with the order Actiniaria

2

plural actiniae

ak-ˈti-nē-ˌē

or actinias : any sea anemone or related animal

Word History

Etymology

borrowed from New Latin, from Greek aktīn-, aktís "ray, beam" + New Latin -ia -ia entry 1

First Known Use

1752, in the meaning defined at sense 1

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!