action painting

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A style of abstract painting that uses techniques such as the dribbling or splashing of paint to achieve a spontaneous effect.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun art A genre of modern art in which the paint is dribbled, splashed or poured onto the canvas to obtain a spontaneous and totally abstract image

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a New York school of painting characterized by freely created abstractions; the first important school of American painting to develop independently of European styles