Maar

Etymology
Attested since at least the 16th century, from an underlying. Adopted into scientific parlance during the 19th century from dialects of the Eifel region, home to many maars, which often include the word in their names. The Central Franconian term also has the broader sense of “pool, cesspit, swamp”, which touches on or is even merged with it (cf. 🇨🇬 and ). Further origin uncertain, but surely related with the root of and. Plausibly a borrowing from, perhaps through.

Noun

 * 1)  maar broad, low-relief volcanic crater caused by a phreatomagmatic eruption