noun A person who is intellectual but generally introverted.
The bullies used to call him a nerd at school.
noun One who has an intense, obsessive interest in something.
a computer nerd
noun A member of a subculture revolving around intellectualism, technology, video games, fantasy and science fiction, comic books and assorted media. .mw-parser-output .defdate{font-size:smaller}
noun One who is stupid and socially inept or unattractive; a social outcast.