Princeton's WordNet(0.00 / 0 votes)Rate this definition: 1  deltoid, deltoid muscle, musculus deltoideus(adj) a large triangular muscle covering the shoulder joint and serving to abduct and flex and extend and rotate the arm. 2  deltoid(adj) triangular or suggesting a capital delta, with a point at the apex.
Founded in 1846, Washington, D.C.'s Smithsonian Institution is the world's largest museum and research center, with 19 museums and galleries, nine research facilities, and the National Zoological Park. Most of these attractions are located in and around the National Mall, between the Lincoln Memorial and the U.S. Capitol.
The museum is located at 2 Massachusetts Ave., N.E., Washington, DC 20002. It is just across 1st Street NE from Union Station. Click Here for Google Map showing the location of the National Postal Museum. Closest Metro Station: The Union Station Metro Station on the Red Line is nearest to the National Postal Museum.