adj. Steep, like a precipice; as, a precipitous cliff or mountain. adj. Headlong; as, precipitous fall. adj. Hasty; rash; quick; sudden; precipitate; as, precipitous attempts. from the GNU version of the Collaborative International Dictionary of English. adj. Steep, like a precipice. adj. Headlong. adj. Hasty; rash; quick; sudden; precipitate.
A'a' lava flow burying a road on Etna (Oct. 2002). Brief explanation: A'a' lava is the most common appearance type of lava flows that cool down forming fragmented, rough, sometimes spiny, or blocky surfaces.
The Neapolitans who lived in the vicinity took the Italian word lava, meaning a stream caused suddenly by rain, and applied it to the streams of molten rock coming down the sides of Vesuvius. The term was then taken into Standard Italian, where it came to mean the rock in both its molten and its solidified states.