Digram refers to two letters or characters in a row. There are several other terms that can be used interchangeably with this word. Bigram is one such word that has the same definition as digram. It is also a term used commonly in computational linguistics. Other synonyms that can be used instead of digram include doublet, couplet, and duet. In mathematics, digraph is used instead of digram to indicate a graph having exactly two points. In summary, all these words are synonyms of digram and can be used interchangeably in most contexts, depending on personal preferences or professional fields where they are commonly used.