from the GNU version of the Collaborative International Dictionary of English
- n. An extensive series of strata, principally developed in the Rocky Mountain region, as in the Laramie Mountains, and formerly supposed to be of the Tertiary age, but now generally regarded as Cretaceous, or of intermediate and transitional character. It contains beds of lignite, often valuable for coal, and is hence also called the lignitic group. See Chart of geology.
from The Century Dictionary and Cyclopedia
- n. See group.
Sorry, no etymologies found.