DCabbr.1. da capo2. direct current3. or D.C. District of Columbia4. Doctor of ChiropracticDis·trict of Columbia (d?s?tr?kt?) Abbr. DC or D.C. A federal district of the eastern United States on the Potomac River between Virginia and Maryland. Coextensive with the city of Washington, it was established by congressional acts of 1790 and 1791 on a site selected by George Washington.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.D.C. (in the US and Canada) abbreviation for (Medicine) Doctor of ChiropracticCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014