David Rashid Osman, 78, a native of Eastern Turkestan, former officer in the Nationalist Chinese Army and U.S. Defense Department linguist, died Dec. 13 at Genesis ElderCare in Silver Spring. He had cancer and suffered from several small strokes. Mr. Osman retired from the Defense Department in 1980 after more than 20 years of service, including duty in Turkey, Iran, Malaysia and Washington. He was fluent in 13 languages or dialects and had a working knowledge of several more. He was born in what was then Urumchi, the capital of Eastern Turkestan, which currently is under Chinese rule. He attended China's Whampoa Military Academy as a young man and was commissioned as an officer in the Nationalist Chinese Army. Fluent in several local languages, he helped facilitate communications among military and government authorities during World War II. At the age of 29, he was a lieutenant colonel and the chief of security for the governor of China's Sinkiang province. Shortly before the Communist takeover in China in 1949, Mr. Osman was assigned to escort a delegation that included U.S. diplomats and U.S. Consul John Hall Paxton to safety in India. This journey included transit over the Himalayas and through mountain passes 18,000 feet above sea level in conditions that included severe cold, oxygen deprivation, shortages of food and hostile forces. After seven weeks they reached New Delhi. When Mr. Osman tried to return to his duty station, the Chinese Communists had closed the border. He was a displaced person for several years, then, with the support of the National Christian Council Relief Committee, he entered the United States in 1953. He was a student and special consultant on Central Asian languages at Georgetown University's Institute of Languages and Linguistics. In the 1950s, he began his Defense Department career, and he subsequently became a U.S. citizen. Mr. Osman, a resident of Rockville, had been active in Scouting organizations. Survivors include his wife of 43 years, Marcia Winslow Howes Osman of Rockville; and four children.