Who is Nerd and meaning of the Nerd?

A nerd is a person seen as overly intellectual, obsessive, introverted or lacking social skills. Such a person may spend inordinate amounts of time on unpopular, little known, or non-mainstream activities, which are generally either highly technical, abstract, or relating to topics of science fiction or fantasy, to the exclusion of more mainstream activities. Additionally, many so-called nerds are described as being shy, quirky, pedantic, and unattractive.

Originally derogatory, the term "nerd" was a stereotype, but as with other pejoratives, it has been reclaimed and redefined by some as a term of pride and group identity. However, the augmentative terms, geek and dork, have not experienced a similar positive drift in meaning and usage.

Nerd

A foolish or contemptible person who lacks social skills or is boringly studious: "one of those nerds who never asked a girl to dance".
An intelligent, single-minded expert in a particular technical discipline or profession.

A nerd is a technically bright but socially inept person. The classic image of the nerd has been the wild-haired genius kid with thick-lensed glasses surrounded by test tubes and computers. Microsoft's Bill Gates is sometimes considered the walking embodiment of the older, successful nerd. As computer technology becomes less frightening and "nerdish" to larger numbers of people, society seems to be developing a more tolerant, even benevolent view of the nerd.

Although the term's origin is obscure, one theory is that it derives from a children's book by Dr. Seuss, If I Ran the Zoo , in which this passage is found:

    And then, just to show them,
    I'll sail to Ka-Troo
    And bring back an it-kutch,
    A preep, and a proo,
    A nerkle, a nerd,
    And a seersucker, too!"

Nerd is a more general term than geek and weenie and is somewhat comparable to propellor head .