THUNDER EGG
Meaning of THUNDER EGG in English
Geol.
a globular concretion of opal, agate, or chalcedony weathered out of tuff or basalt. Cf. geode .
[ 1940-45 ]
Random House Webster's Unabridged English dictionary.
Полный английский словарь Вебстер - Random House .
2012