"Fluxus an art movement begun in 1961/1962, which flourished throughout the 1960s, and into the 1970s. Characterized by a strongly Dadaist attitude, Fluxus promoted artistic experimentation mixed with social and political activism, an often celebrated anarchistic change. Although Germany was its principal location, Fluxus was an international avant-garde movement active in major Dutch, English, French, Swedish, and American cities. Its participants were a divergent group of individualists whose most common theme was their delight in spontaneity and humor. Fluxus members avoided any limiting art theories, and spurned pure aesthetic objectives, producing such mixed-media works as found poems, mail art, silent orchestras, and collages of such readily available materials as scavanged posters, newspapers, and other ephemera. Their activities resulted in many events or situations, often called "Aktions" — works challenging definitions of art as focused on objects -- performances, guerilla or street theater, concerts of electronic music — many of them similar to what in America were known as Happenings.
In Latin and other languages, "Fluxus" literally means "flow" and "change." Similarly, the related English word "flux" is used variously to mean "a state of continuous change," "a fusion," and "a gushing of fluid from a body."
From Art Lex Art Dictionary, http://www.artlex.com/ArtLex/f/fluxus.html