n. 1. A loose, negligent dress; ordinary dress, as distinguished from full dress. [ 1913 Webster ]
2. (Mil. & Naval) An authorized habitual dress of officers and soldiers, but not full-dress uniform. [ 1913 Webster ]
Undress parade (Mil.), a substitute for dress parade, allowed in bad weather, the companies forming without arms, and the ceremony being shortened. [ 1913 Webster ]