An icicle is a long, thin, pointed piece of ice that hangs down from a roof, a window, a branch, or a pipe when dripping water freezes in cold weather. It is usually thicker at the top and comes to a sharp point at the bottom. People are often told not to stand under a big one, because it can fall. This is the ordinary English word; we do not normally say “ice stick”. It is ice plus an old piece ickle, which already meant a bit of ice. Later the spelling moved toward other nouns ending in -icle. An ice cube is a small block in a drink; an iceberg is a huge mass floating in the sea — neither of those is an icicle.