1915- 20; probably variant of geck (mainly Scots) fool < Dutch or Low German gek

Geek and nerd : are they marginalized rejects or cool pop culture specialists? It depends on the era in which these slang labels were applied.
In the first half of the 20th century, geek was the word for a circus sideshow performer who bit the heads off small live animals. Geeks were meant to put on horrifying spectacles for the normal people in the audience. Through what linguists call “semantic drift” (gradual change in meaning), a slang use of geek emerged in the popular culture of the 1980s to designate a newly marginalized group: smart and tech-savvy—but socially awkward—young enthusiasts of emerging computer technologies.
The term nerd in the second half of the 20th century similarly described an unpopular, overly intellectual young person who was interested in science or math. The stereotypical high school or college nerd was picked on by the stereotypical jock and never stood a chance with the pretty, popular girl. Nerds were not considered cool.
But in the 21st century, both words evolved to become nearly synonymous, and labels no longer to be ashamed of. Twenty-first century geeks and nerds are smart people of all ages (and genders) who are well-informed and care passionately about something. Though often an expert in technology, science, or math, a nerd or geek can be a specialist or fan of almost any subculture imaginable: a French-cuisine geek or a Jane Austen nerd .
Today these labels are not predominantly used to stigmatize. What changed? First, mainstream pop culture embraced science fiction toward the end of the 20th century. Sci-fi was no longer a private niche of films and comic books, known only to fans of the genre. Films like 2001: A Space Odyssey , Alien , and Star Wars became common cultural touchstones. Also, computer technology infiltrated almost every aspect of 21st-century life. The specialists in that technology, once belittled for their interests, became valued and pivotal members of society. Further, the Internet has helped people to find like-minded peers who share otherwise specialized and possibly isolating interests, connecting and creating thriving communities.
Geek and nerd , terms with a painful and exclusionary history, are not always appropriate labels to force on someone else. However, they are increasingly used by people to refer to themselves and others in reappropriated and validating ways. When used to mean specialist or enthusiast, geek and nerd need not be considered offensive labels at all.