'Duograph' definitions:

Definition of 'Duograph'

From: GCIDE

Duograph \Du"o*graph\, n. [L. duo two + -graph.] (Photo-engraving) A picture printed from two half-tone plates made with the screen set at different angles, and usually printed in two shades of the same color or in black and one tint. [Webster 1913 Suppl.]