1. a pair of letters or characters that together represent a single sound or phoneme
Usage: linguistics; also called digraph
2. an instrument for drawing or copying diagrams and designs mechanically
Usage: technical; archaic

Examples

• In English, 'th' is a diagraph representing a single sound.
• The diagraph 'ch' in 'church' stands for one distinct phoneme.
• Students learn to identify diagraphs when studying phonics.
• The letter combination 'sh' is a common diagraph in English.
• Diagraphs are important in understanding how written language maps to spoken sounds.