Old English scytel "a dart, arrow," from West Germanic *skutilaz (cf. Old Norse skutill "harpoon"), from PIE *skeud- "to shoot, to chase, to throw, to project" (see shoot (v.)). The original sense in English is obsolete; the weaving instrument so called (mid-14c.) from being "shot" across the threads. Sense of "train that runs back and forth" is first recorded 1895, from image of the weaver's instrument's back-and-forth movement over the warp; extended to aircraft 1942, to spacecraft 1969. In some other languages, the weaving instrument takes its name from its resemblance to a boat (cf. Latin navicula, French navette, German weberschiff).