from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A flatbottom, roughly circular volcanic crater of explosive origin that is often filled with water.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. a broad volcanic crater, usually filled with a lake
from The Century Dictionary and Cyclopedia
- n. In geology:
- n. A local German name originally applied to certain small crater-lakes in the recently extinct volcanic region of the Eifel, near Bonn, on the Rhine. The craters were believed to have resulted from explosive outbreaks, without emissions of lava.
- n. Technically, any crater which has been produced by an explosion unaccompanied by lava.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a flat-bottomed volcanic crater that was formed by an explosion; often filled with water
German, from Vulgar Latin *mara, standing water, lake, from Latin mare, sea; see mare2.(American Heritage® Dictionary of the English Language, Fourth Edition)
From dialectal German Maar. (Wiktionary)