Presupposition

From Wikinfo

In Pragmatics (Linguistics): Implicit assumptions about the world. They are required to make an utterance meaningful.

Do you want to do it again? (Presupposition: You have done it already, at least once.)

My wife is pregnant. (Presupposition: I have a wife.)

Much of the information that is exchanged in discourse happens in the form of presuppositions.

This differs from entailment and implication.

References

• Adapted from the Wikipedia article, "Presupposition" http://en.wikipedia.org/wiki/Presupposition, used under the GNU Free Documentation License