What is a word called that consists of a repetition of one word?
Solution 1:
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:
http://en.wiktionary.org/wiki/Category:English_reduplications
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
Solution 2:
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...