The term 'olive DRAB' is a military uniform color that was used by the United States Army during World War II. It is a dull, dark greenish-brown color that was designed to blend in with the natural environment. The term 'DRAB' is derived from the Middle English word 'drabbe', which means dull or dreary. The olive DRAB color is still used today by the U.S. military and other armed forces around the world.