'Digraph' definitions:
Definition of 'digraph'
(from WordNet)
noun
Two successive letters (especially two letters used to represent a single sound: `sh' in `shoe') [syn: digraph, digram]
Definition of 'Digraph'
From: GCIDE
- Digraph \Di"graph\, n. [Gr. di- = di`s- twice + ? a writing, ? to write.] Two signs or characters combined to express a single articulated sound; as ea in head, or th in bath. [1913 Webster]