Bethesda, uninc. city (1990 pop. 62,936), Montgomery co., W central Md., an affluent residential and commercial suburb of Washington, D.C. The area was settled in the late 17th cent. and takes its name from the 1820 Bethesda Presbyterian Church. The National Institutes of Health (1939), the Food and Drug Administration, the National Institute of Standards and Technology, and the Walter Reed National Military Medical Center are there, along with many private research facilities.