The Collaborative International Dictionary of English v.0.48:
grapheme \graph"eme\ n. (Linguistics) a written symbol that is used to represent speech. Syn: character, graphic symbol. [WordNet 1.5] GraphicWordNet (r) 3.0 (2006):
grapheme n 1: a written symbol that is used to represent speech; "the Greek alphabet has 24 characters" [syn: character, grapheme, graphic symbol]