*ding-dong*

n. [ See Ding. ] 1. The sound of, or as of, repeated strokes on a metallic body, as a bell; a repeated and monotonous sound. [ 1913 Webster ]

2. (Horol.) An attachment to a clock by which the quarter hours are struck upon bells of different tones.

3. a stupid or foolish person; -- used in a deprecatory or contemptuous sense. [ slang ]
Syn. -- ding-a-ling, doofus. [ PJC ]