Full Idea
We could say that the language has more than one correct way of being mapped onto the world (it must, since it has more than one way of being correctly mapped onto a language which is itself correctly mapped onto the world).
Gist of Idea
Language maps the world in many ways (because it maps onto other languages in many ways)
Source
Hilary Putnam (Meaning and the Moral Sciences [1978], Pt Four)
Book Reference
Putnam,Hilary: 'Meaning and the Moral Sciences' [RKP 1981], p.135
A Reaction
This spells out nicely the significance of Quine's 'indeterminacy of translation'. Others have pointed out that the fact that language maps onto world in many ways need not be anti-realist; the world is endless, and language is limited.