That which is heteronymous; a thing having a different name or designation from some other thing; -- opposed to homonym.

two words are heteronyms if they are spelled the same way but differ in pronunciation (e.g. `bow')

a kind of homonym

a full-fledged character, complete with biographical details

Term coined by the Portuguese poet Fernando Pessoa to describe an alter ego through which poets/authors can create work.

The literary concept of heteronym, invented by Portuguese poet Fernando Pessoa, refers to one or more imaginary character(s) created by a poet to write in different styles. Heteronyms differ from nom de plumes in that the latter are just false names, while the former are characters having their own supposed physiques, biographies and writing styles.