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.
Young Niana Guerrero drops everything to dance wherever she is to the world's No. 1 song, Despacito. Her video has been viewed more than 69 million times. This week, it became the most streamed song in history. Universal Music says the official version and a remix have been streamed 4.6 billion times since the original release six months ago.