The usual Old English word for cloud was weolcan. In Middle English, skie also originally meant cloud. The four fundamental types of cloud classification (cirrus, cumulus, stratus, nimbus) were proposed by British amateur meteorologist Luke Howard (1772-1864) in 1802. Figuratively, as something that casts a shadow, from early 15c.; hence under a cloud (c.1500).
Thanks for the A2A. Okay, the most famous song in the world is no doubt 'Happy Birthday', followed by various Christmas carols (since the majority of human population is Christian indeed and since Santa is a really famous guy), folk songs, army marches and national anthems.
What is the most known song in the whole world? Say, a song that anybody from New York City to the native tribes in Indonesia can sing the lyrics or hum the music to, even when they don't know the title or singer. My answer: Some of them are: We are the World by Michael Jackson and Lionel Richie. Blowing in the Wind by Bob Dylan.