from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The petrified fruit of Chara hispida, a species of stonewort.
from the GNU version of the Collaborative International Dictionary of English
- n. The petrified fruit of the Chara hispida, a species of stonewort. See stonewort.
from The Century Dictionary and Cyclopedia
- n. A petrified spiral seed-vessel of plants of the genus Chara, found in fresh-water deposits, and formerly supposed to be a shell.
Ancient Greek circle, ring + fruit. (Wiktionary)