half·tone 
(hăftōn′, häf-)
(hăftōn′, häf-)n.
1. A tone or value halfway between a highlight and a dark shadow.
2.
a. A picture in which the gradations of light are obtained by the relative darkness and density of tiny dots produced by photographing the subject through a fine screen.
b. A picture made by such a process.
3. Music See semitone.