Half tone

Half tone \Half tone\, or Half-tone \Half"-tone`\, n.
   1. (Fine Arts) An intermediate or middle tone in a painting,
      engraving, photograph, etc.; a middle tint, neither very
      dark nor very light.
      [Webster 1913 Suppl.]

   2. (Music) A half step.
      [Webster 1913 Suppl.]

   3. A print obtained by the half-tone photo-engraving process.
      [WordNet sense 1]
      [PJC]

   4. the etched plate used to reproduce a half-tone
      illustration. [WordNet sense 4]

   Syn: halftone engraving, photoengraving.
        [WordNet 1.5]