Where did the term Dada come from, and what does it mean?

In the years before World War I, Europe appeared to be losing its hold on reality. Einstein’s universe seemed like science fiction, Freud’s theories put reason in the grip of the unconscious and Marx’s Communism aimed to turn society upside down, with the proletariat on top. The arts were also coming unglued. Schoenberg’s music was atonal, Mal-larmé’s poems scrambled syntax and scattered words across the page and Picasso’s Cubism made a hash of human anatomy.