\Half tone\, or Half-tone \Half"-tone`\, n.
1. (Fine Arts)
   (a) An intermediate or middle tone in a painting,
       engraving, photograph, etc.; a middle tint, neither
       very dark nor very light.
   (b) A half-tone photo-engraving.
2. (Music) A half step.

\Half"-tone`\, a.
Having, consisting of, or pertaining to, half tones; specif.
(Photo-engraving), pertaining to or designating plates,
processes, or the pictures made by them, in which gradation
of tone in the photograph is reproduced by a graduated system
of dotted and checkered spots, usually nearly invisible to
the unaided eye, produced by the interposition between the
camera and the object of a screen. The name alludes to the
fact that this process was the first that was practically
successful in reproducing the half tones of the photograph.