Geek meaning : A carnival performer specializing in bizarre and unappetizing behavior. A person who is intensely interested in a particular field or hobby and often having limited or nonstandard social skills. Often used with an attributive noun. (by extension) An expert in a technical field, particularly one having to do with computers. The subculture of geeks; an esoteric subject of interest that is marginal to the social mainstream; the philosophy, events, and physical artifacts of geeks; geekness. An unfashionable or socially undesirable person. To behave geekishly or in a socially awkward manner, especially when under the influence of drugs or other psycho-active substances, and exhibiting such marked characteristics as hyperactivity, repetitiveness, talkativeness, nervousness, irritability, or paranoia.