A Cloud

1. (obsolete) A rock; boulder; a hill.
2. A visible mass of water droplets suspended in the air.
3. Any mass of dust, steam or smoke resembling such a mass.
4. Anything which makes things foggy or gloomy.
5. (figuratively) Anything unsubstantial.
6. A dark spot on a lighter material or background.
7. A group or swarm, especially suspended above the ground or flying.
8. An elliptical shape or symbol whose outline is a series of semicircles, supposed to resemble a cloud.
9. (computing, with "the") The Internet, regarded as an abstract amorphous omnipresent space for processing and storage, the focus of cloud computing.
10. (figuratively) A negative or foreboding aspect of something positive: see every cloud has a silver lining or every silver lining has a cloud.
11. (slang) Crystal methamphetamine.
12. A large, loosely-knitted headscarf worn by women.