moya noun1 •(no longer used) Flowing mud associated with a volcanic eruption (especially in South America), formed when snow or a lake near a volcano is disrupted, or when rain or steam mixes with soil or ash during an eruption.These are the principal tufas indicative of the boiling tufaceous mud, or moya, which once filled, even to an overflow, the valley of Rieden. — 1832 formsmoyas
