the.com/lava flow

means A stream of molten rock that has erupted from a volcano or fissure and flows across the land until it cools and hardens.

from "Lava" traces back to Italian, where it described a stream flowing downhill — likely tied to Latin "labes" (a fall or slide) or "lavare" (to wash), since the word was first used around Naples and Vesuvius for the rivers that gush down streets after heavy rain, and then got borrowed to name the glowing rivers the volcano itself sent down. "Flow" is just honest Old English, from "flowan," to flow — no drama needed there, the rock supplies plenty.