digraph
dig·raph
noun
1.
two successive letters (especially two letters used to represent a single sound: `sh'' in `shoe'')
Origin
From Ancient Greek δίς (dís, “double”) + γράφω (gráphō, “write”), equivalent to di- + -graph.
Related words
Broader terms
WordNet 2.1 (Princeton University). Wiktionary (CC BY-SA). CMU Pronouncing Dictionary. WordNet 2.1 Copyright Princeton University. All rights reserved. Wiktionary content is available under the Creative Commons Attribution-ShareAlike Licence.