tautonyms

Noun

tautonym (plural tautonyms)

1. A binomial name consisting of the same word twice, such as Bison bison.
   • And that would mean a species named Leucanthemum leucanthemum, with the genus and species epithet the same (a tautonym), which is a total no-no in botany.2013 August 14, “Is oxeye daisy a Leucanthemum or a Chrysanthemum?”, in Botanical Accuracy
2. A word or term made from two identical parts or syllables, such as bonbon or dada.
   • The chapter on reduplication - "flip-flopping higgledy- piggledy through the riffraff" - differentiates rhyming compounds like bigwig, hotshot, ragtag, sci-fi from repetitions called tautonyms, such as bye-bye, so-so, rah-rah, as well as from ricochet words in which the repeated element is...2006 March 11, William Safire, “Language: Nifty gifties: Books full of words - Opinion - International Herald Tribune”, in The New York Times
3. An absolute synonym.