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n. Lava with a smooth ropy surface.

n. A form of lava flow of basaltic rock, usually dark-colored with a smooth or ropey surface. It is one of two chief forms of lava flow emitted from volcanoes of the Hawaiian type, the other form being aa.

n. A name given in Hawaii (formerly the Sandwich Islands) to lava having a relatively smooth or billowing surface, in distinction from the rough-surfaced lava, called aa.

n. Compact lava. The spongy or rough lava is called a-a.

n. freely flowing lava

"From this grove we travelled as before in single file over an immense expanse of lava of the kind called pahoehoe, or satin rock, to distinguish it from the a-a, or jagged, rugged, impassable rock."

aa   

lava