1. A taxonomic designation in which the genus and species names are the same; for example, Gorilla gorilla (the gorilla), Mephitis mephitis (striped skunk), and Chloris chloris (the greenfinch). This is okay in zoology, but is no longer considered acceptable in botany.
2. A word composed of two identical parts, for example tomtom, tutu, or goody-goody.
Etymology: From the Greek roots tauto-, meaning identical, and -nym, meaning name.