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.
A lava flow is a moving outpouring of lava, which is created during a non-explosive effusive eruption. When it has stopped moving, lava solidifies to form igneous rock. The term lava flow is commonly shortened to lava. Explosive eruptions produce a mixture of volcanic ash and other fragments called tephra, rather than lava flows.