American Indian Movement n (Government, Politics & Diplomacy) a militant movement or grouping of American Indians, organized in 1968 to combat discrimination, injustice, etc Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014