Nerd, as a stereotypical or archetypal designation, refers to somebody who is perceived to be of above-average intelligence and whose interests are not shared by mainstream society. Most people's interests are in the subjects of sports, music, fashion, food, etc., but nerds typically have interests that are more encyclopedic. The term is mostly widely used in the United States, but also has some currency in other English speaking countries such as Canada, Australia, and New Zealand.
For quite some time in the latter 20th Century, the term "nerd" was generally considered derogatory, and was a common insult, especially among school-age boys. However, beginning in the late 1990s, many nerds on the Internet reclaimed the word nerd as a badge of pride and began using it as a positive description of a technically-competent person. Although traditionally used to describe men and boys, the terms "nerd" and " geek" have been adopted by many women interested in technology, science, mathematics and other typically male-dominated intellectual fields as badges of their accomplishments in these areas.
The term "nerd", meaning " square" goes back at least to 1951, when Newsweek reported the usage as relatively new in Detroit. By the 1960s, it took on connotations of bookishness as well as social ineptitude. The word itself first appeared in Dr. Seuss's book If I Ran the Zoo, published in 1950, where it simply names one of Seuss's many comical imaginary animals. (The narrator Gerald McGrew claims that he would collect "a Nerkle, a Nerd, and a Seersucker too" for his imaginary zoo.) Another theory of the word's origin sees it as a variation on Mortimer Snerd, the name of Edgar Bergen's ventriloquist dummy. Yet another theory traces the term to Northern Electric Research and Development, suggesting images of employees wearing pocket protectors with the acronym N.E.R.D. printed on them. Finally, oral history at Rensselaer Polytechnic Institute holds that the word was coined there, spelled as "knurd" ("drunk" spelled backwards), to describe those who studied rather than partied. (This usage predates a similar coinage of " knurd" by author Terry Pratchett.) The term itself was used heavily in the American 1974-84 television comedy Happy Days which took place in Milwaukee, Wisconsin and had been set in the mid-1950s.