1920, from French dada "hobbyhorse," child's nonsense word, selected 1916 by Romanian poet Tristan Tzara (1896-1963), leader of the movement, for its resemblance to meaningless babble.

Freedom: DADA DADA DADA, the howl of clashing colors, the intertwining of all contradictions, grotesqueries, trivialities: LIFE. [T. Tzara, "Dada Manifesto," 1918]

Related: Dadaist; Dadaism.

dada (n.)

child's word for "father," 1680s; see dad.

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Definitions of Dada from WordNet

dada (n.)
an informal term for a father; probably derived from baby talk;
Synonyms: dad / daddy / pa / papa / pappa / pop
dada (n.)
a nihilistic art movement (especially in painting) that flourished in Europe early in the 20th century; based on irrationality and negation of the accepted laws of beauty;
Synonyms: dadaism