The Collaborative International Dictionary of English v.0.48:

Tambour \Tam"bour\, n.
   1. (Mus.) A kind of small flat drum; a tambourine.
      [1913 Webster]

   2. A small frame, commonly circular, and somewhat resembling
      a tambourine, used for stretching, and firmly holding, a
      portion of cloth that is to be embroidered; also, the
      embroidery done upon such a frame; -- called also, in the
      latter sense, tambour work.
      [1913 Webster]

   3. (Arch.) Same as Drum, n., 2
      (d) .
          [1913 Webster]

   4. (Fort.) A work usually in the form of a redan, to inclose
      a space before a door or staircase, or at the gorge of a
      larger work. It is arranged like a stockade.
      [1913 Webster]

   5. (Physiol.) A shallow metallic cup or drum, with a thin
      elastic membrane supporting a writing lever. Two or more
      of these are connected by an India rubber tube, and used
      to transmit and register the movements of the pulse or of
      any pulsating artery.
      [1913 Webster]