Hazel R. (Chapin) Adams, 84, of 10 Old Diamond Hill Road, formerly of Auburn, a World War II veteran, died Saturday, April 19, in Sturdy Memorial Hospital after an illness.Her husband, Thomas R. Adams, died in 1989. She left a son, Howard C. Adams of Cumberland; a daughter, Nancy R. Dignan of Oakham, Mass.; a sister, Marion Lundgren of Torrington, Conn.; two grandchildren; several nephews and nieces. Two brothers, Robert and Correll Chapin, predeceased her.    She was born in Sheffield, Mass., daughter of Albert and Ruth (Armstrong) Chapin, and lived in Auburn for 50 years. She was educated in Sheffield schools, and later graduated from the University of Massachusetts — Amherst. She was an Army veteran of World War II, and held the rank of first lieutenant.Mrs. Adams was a librarian and worked at the Town of Auburn Public Library for many years. She was also a registered dietitian. She was a member of the First Congregational Church of Auburn and its Women's Fellowship. She enjoyed travel, gardening and bird watching.   The funeral service was held in First Congregational Church, 128 Central St. Burial was in Worcester County Memorial Park, Paxton.  Memorial donations may be made to First Congregational Church Memorial Fund, c/o First Congregational Church of Auburn, 128 Central St., Auburn, MA 01501 or to the American Heart Association, 20 Speen St., Framingham, MA 01701. Britton-Wallace Funeral Home, 91 Central St., Auburn directed arrangements.