The Boston meaning derived from the movie " West Side Story" in 1961. The meaning came from the movie in which the gangs of NYC would use the word " cool ". In Somerville, Ma. in the hub of Boston, Jim Labadini orchestrated the use of this word through out the Somerville school system over 4,000 students. This was intended to be a word that would be unique to kids in Somerville to use to express " how cool" something is in their own terminology. It quickly caught on through out Greater Boston.

Music so good it could elicit sexual arousal.

New England slang that adds emphasis. Synonymous with really, very and hella.

To describe how great something is: "This car is wicked cool!"
To show aggravation: "This fucking guy is a wicked asshole!"
To show frustration: "That guy is wicked slow!"
To show amazement: "Wow, that game is wicked awesome!"
To describe a person: "She's a wicked bitch!"
To describe the weather: "Man, it's wicked hot out here!"
To emphasize feelings: "That story made me wicked sad!"
To exaggerate your point: "That took a wicked long time!"

US ---> really,very, extremely
UK ---> cool, good, great, funky
France ---> (as 'terrible') great

origins: Boston, Massachusetts, but is now commonly used all over New England. If you're from Iowa (or anywhere that isn't New England) and you use this word, you sound like a dumb ass.

Definition: very, really, so, totally.

MASS. version of the word "really"

(very) -Boston origins