An Etymological Dictionary of Astronomy and Astrophysics

A large, roughly circular, → crater with diameter at least three or four times depth on the summit or in the side of a → volcano. A caldera can form from a volcanic blast or the collapse of a volcanic cone into an emptied → magma chamber.

Etymology (EN): From Sp. caldera “cauldron, kettle,” also name of a crater on Canary Islands, from L. caldarius “of warming,” from calidus “warm, hot,” → calorie.

Etymology (PE): Tiyân “large cauldron; cauldron used for warming water in a communal bathhouse,” of unknown origin.