digraph
di.graph \'di--.graf\ \di--'graf-ik\ \-'graf-i-k(*-)le-\ n 1: a group of two successive letters whose phonetic value is a single sound (as ea in bread) or whose value is not the sum of a value borne by each in other occurrences (as ch in chin) 2: a group of two successive letters - di.graph.ic aj