What is a word called that consists of a repetition of one word?

I came across the word polypoly in one of the other question asked on the site, and it got me thinking whether there are other English words that are made up of a word or part of a word repeated in the same way that polypoly is made up of poly + poly. Can you please provide examples also?

  • 2
    The word was actually polyopoly, if I remember correctly, not polypoly.
    – Pockets
    May 21, 2014 at 22:53
  • I think both are acceptable spellings, according to the post anyway: english.stackexchange.com/questions/171868/… May 21, 2014 at 23:41
  • This question is not too broad. He said "some" examples, we cannot list all of them obviously. Also, we know what it is called now so more examples can be searched. There are similar list-request questions in the past that is open also.
    – ermanen
    May 22, 2014 at 0:14
  • @Michael Lai: You may modify the question title and body to ask what this formation is called instead of asking for examples only. And you can ask for some examples in the question body.
    – ermanen
    May 22, 2014 at 0:27
  • They'll be matched by the regexp ^(.*)-?\1$ May 22, 2014 at 1:34

3 Answers 3


This is called reduplication. If you repeat the whole word (or lexeme), it is called full reduplication. There is usually a hyphen in between. (For example: go-go)

There is a list of English reduplications here:

Full reduplication examples:

  • boo-boo
  • bye-bye
  • cancan
  • chop-chop
  • gee-gee
  • jaw-jaw
  • licky-licky
  • moo-moo
  • murmur
  • nulla-nulla
  • pee-pee
  • pompom
  • poo-poo
  • pooh-pooh
  • rah-rah
  • tartar
  • dodo
  • lulu
  • tutu
  • juju
  • papa
  • couscous
  • tete
  • coco
  • dik-dik
  • beriberi
  • 5
    ... and a look-alike: hotshots May 21, 2014 at 23:14
  • 2
    @teylyn: Loan words are English also.
    – ermanen
    May 22, 2014 at 1:05
  • 4
    It may be worth noting that testes is not reduplicated, but rather the plural form of testis.
    – Anonym
    May 22, 2014 at 1:59
  • 1
    @ermanen Note that testis, testes follows a specific Latin declension in which singular -is is replaced with plural -es. Some other nouns belonging to the same declension: axis, axes; thesis, theses; oasis, oases. So testes does appear to have been reduplicated, but the process by which it has been created is not reduplication.
    – Anonym
    May 22, 2014 at 2:42
  • 1
    @ermanen Perhaps. If it were asked as a broader question about what exactly constitutes reduplication, then I think that it might be interesting.
    – Anonym
    May 22, 2014 at 2:56

To supplement ermanen's list, I note these from Merriam-Webster's Eleventh Collegiate Dictionary (2003):

ack-ack (n.)

agar-agar (n.)

atlatl (n.)

aye-aye (n.)

Berber (n.)

bonbon (n.)

buddy-buddy (adj.)

bulbul (n.)

caracara (n.)

cha-cha (n.)

chowchow (n.—the relish not the dog, which is spelled chow chow)

dumdum (n.—the bullet)

dum-dum (n.—the nitwit)

gaga (adj.)

go-go (adj.)

goody-goody (adj.)

goo-goo (adj. & n.)

gris-gris (n.)

ha-ha (interj.)

ha-ha (n.—a sunk fence)

lavalava (n.—has nothing to do with volcanic lava)

mau-mau (v.)

meme (n.)

motmot (n.)

mumu (n., from MW's Unabridged dictionary)

no-no (n.)

pawpaw (n.)

so-so (adj. & adv.)

tsetse (n.)

tut-tut (interj. & v.)

For some reason, Merriam-Webster's doesn't acknowledge the reality of hubba-hubba. But I'm sure that there are others in the dictionary that I've missed...

  • +1 Thanks for the help :) I learned some new words also!
    – ermanen
    May 22, 2014 at 2:14
  • Out of context and just scrolling, these answers are absolutely hilarious.
    – njboot
    May 22, 2014 at 3:17

Such a word is a tautonym. See sense 2 here: "(linguistics) A word or term made from two identical parts or syllables, such as bonbon or dada."

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