n.1. Any of various aircraft or schemes for lifting and transporting heavy objects from a position in the air or in space, usually by means of a long cable.
2. Informal Something that is depended on despite seeming impossible or rationally inexplicable: "We should not look for skyhooks, but only for toeholds" (Richard Rorty).
3. Basketball A hook shot that is released so high it is nearly impossible to block.