Stalacite means a deposit that hangs like an icicle from the roof of a cave.
A good way to remember the two words stalacite and stalagmite is: Stalacite has a C in it so that can represent ceiling and stalagmite has a G in it which can represent ground.
A stalactite ("c" in the middle) is a growth of crystalline calcite precipitated from solution in the ground-water feeding it, and growing downwards from a water-carrying joint in the roof of a limestone cave.
Its opposite number, growing up from the floor, is a stalagmite.
Precipitation and crystallisation of calcite (calcium carbonate) from the ground-water that has dissolved it from the limestone above the cave.
Both are calcite (crystalline calcium carbonate) formations in caves. . Stalactites grown down from the cave roof: "C" for ceiling, and it hangs on tight! . Stalagmites grow up from the floor' "G" for ground, and it might reach the ceiling - or the stalactite growing down towards it, and when they fuse the result is a Column.