Digraphs refer to a combination of two letters that represents a single sound. Synonyms for the term "digraphs" include letter pairs, two-letter blends, grapheme clusters, consonant clusters, and double letters. Letter pairs are two letters standing together that represent a single phoneme. Two-letter blends are two adjacent letters that make a sound distinct from the sounds of the two individual letters. Grapheme clusters are sequences of letters that represent a particular sound or group of sounds. Consonant clusters are two or three consonant sounds that appear together in a word. Finally, double letters are identical letters that appear consecutively in a word. Overall, these synonyms capture the essence of what digraphs are and how they function in language.