Chromatium

noun

Chro·​ma·​ti·​um

krōˈmāshēəm

: a genus of purple sulfur bacteria (family Thiorhodaceae) that are ovoid to bean-shaped or rod-shaped, motile by polar flagella, reddish from a mixture of bacteriochlorophyll and carotenoid pigments, and widely distributed in fresh or salt water, some having been reported also from soil

Word History

Etymology

New Latin, from chromat- + -ium

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!