The Collaborative International Dictionary of English v.0.48:

Tatouay \Tat"ou*ay\, n. [Of Brazilian origin; cf. Pg. tatu, F.
   tatou.] (Zool.)
   An armadillo (Xenurus unicinctus), native of the tropical
   parts of South America. It has about thirteen movable bands
   composed of small, nearly square, scales. The head is long;
   the tail is round and tapered, and nearly destitute of
   scales; the claws of the fore feet are very large. Called
   also tatouary, and broad-banded armadillo.
   [1913 Webster]