Abstract: The mainstream view in philosophy of language is that sentence meaning determines truth-conditions. A corollary is that the truth or falsity of an utterance depends only on what words mean and how the world is arranged. Although several prominent philosophers (Searle, Travis, Recanati, Moravcsik) have challenged this view, it has proven hard to dislodge. The alternative view holds that meaning underdetermines truth-conditions. What is expressed by the utterance of a sentence in a context goes beyond what is encoded in the sentence itself. Truth-conditional content depends on an indefinite number of unstated background assumptions, not all of which can be made explicit. A change in background assumptions can change truth-conditions, even bracketing disambiguation and reference assignment. That is, even after disambiguating any ambiguous words in a sentence and assigning semantic values to any indexical expressions in the sentence, truth-conditions may vary with variations in the background.