Definition of the term "geek"

According to Wikipedia:

The word geek is a slang term, noting individuals as "One who is perceived to be overly obsessed with one or more things including those of intellectuality, electronics, etc."[1] Formerly, the term referred to a carnival performer often billed as a wild man whose act usually includes biting the head off a live chicken, bat, snake or bugs. The 1976 edition of the American Heritage Dictionary included only the definition regarding geek shows.