Home › Words › H › heterogramheterogramheterogram · noun — A word or phrase in which no letter occurs more than once.Definition from Wiktionary (CC BY-SA 3.0).EtymologyFrom hetero- + -gram.nounA word or phrase in which no letter occurs more than once.The spelling of a foreign language used as a logogram/ideogram.Definitions & examples from Wiktionary (CC BY-SA 3.0).