The New England-style use of wicked originated is just one of many mysteries of vernacular. For more mysteries of vernacular lessons, take a look at TED-Ed's Mysteries of Vernacular series. Each of the 26 lessons focus on one word that is often used by English speakers. A history of the word's origins and evolution of its use is featured in each video lesson. The entire playlist is embedded below beginning with the word "yankee."
Words of the World. Words of the World is a collection of videos featuring historians and linguists explaining the origins of and history of the use of words in the English language. The videos attempt to put the words into a somewhat modern context. For example this video about the word "guerrilla" makes reference to Che Guevara. The video I've embedded below explains the word "coup."
Langscape is an interactive map created at the Maryland Language Science Center. The Langscape interactive map displays more than 6,000 markers representing more than 6,000 languages. Each marker represents the native language of that location. Zoom-in and click on a marker to learn more about the language. When you click on the marker you will be able to find more information about that marker through links to pages on Ethnologue, Language Archives, and Wikipedia. Those pages will provide information about whether or not the language is extinct and its origins.