Definition: A broad, low relief crater that results from a phreatic eruption or explosion caused by groundwater contact with hot lava or magma. The maar typically fills with water to form a relatively shallow crater lake.
Definition: Organism produces a vocalization that is either structurally more complex or that serves a different function (namely, being used in courtship or pair bond maintenance) than any vocalizations described for that organism that are referred to as "calls" in the literature.