Heteronym may refer to:
The literary concept of heteronym, invented by Portuguese writer and poet Fernando Pessoa, refers to one or more imaginary character(s) created by a writer to write in different styles. Heteronyms differ from noms de plume (or pseudonyms, from the Greek "False Name") in that the latter are just false names, while the former are characters having their own supposed physiques, biographies and writing styles.
In Pessoa's case, there are at least 70 heteronyms (according to the latest count by Pessoa's editor Teresa Rita Lopes); some of them are relatives or know each other; they criticise and translate each other's works. Pessoa's three chief heteronyms are Alberto Caeiro, Ricardo Reis and Álvaro de Campos; the latter two consider the former their master. There are also two whom Pessoa called semi-heteronyms, Bernardo Soares and the Baron of Teive, who are semi-autobiographical characters who write in prose, "a mere mutilation" of the Pessoa personality. There is, lastly, an orthonym, Fernando Pessoa, the namesake of the author, who also considers Caeiro his master.
A heteronym (also known as a heterophone) is a word that is written identically but has a different pronunciation and meaning. In other words, they are homographs that are not homophones. Thus, row (propel with oars) and row (argument) are heteronyms, but mean (intend) and mean (average) are not (since they are pronounced the same). Heteronym pronunciation may vary in vowel realisation, in stress pattern (see also Initial-stress-derived noun), or in other ways: