The story
Etymology from Wiktionary, CC BY-SA 4.0.
Today it means: A large structure created by building a framework (which can itself be a lavacast) and pouring lava over it, and then water, which transforms the lava into cobblestone blocks. Commonly used to quickly cover a large area without manually placing blocks. Full definition →
Etymology from Wiktionary, CC BY-SA 4.0.