- (botany) literally "with the same type". In botanical nomenclature a homotypic synonym (nomenclatural synonym) is a synonym that comes into being through a nomenclatural act
- when a taxon gets a new name, without being included in another taxon (of the same rank). The old name becomes a homotypic synonym of the new name.
- when a new name for a taxon is coined without displacing the existing name, the new name becomes a homotypic synonym.
- The zoological equivalent is "objective synonym".