Sixty six letter words that repeat themselves
1 motmot (tropical bird)
2 cancan (French dance)
3 dumdum (soft-nosed bullet)
4 bye-bye (form of goodbye)
5 zoozoo (a dove or pigeon, sometimes zouzou)
6 haw-haw (a ha-ha, a fenced ditch)
7 chichi (self-consciously stylish)
8 akeake (type of tree)
9 valval (relating to a valve)
10 grigri (African amulet)
11 tzatza (Black Sea fish)
12 humhum (cotton cloth)
13 mulmul (muslin cloth)
14 boo-boo (a blunder [...]