Word learning is typically studied as a problem in which children need to learn a single meaning for a new word. According to most theories, children’s learning is itself guided by the assumption that a new word has only one meaning. However, most words in languages are polysemous, having many related and distinct meanings. In this article, we consider the implications of this disjuncture. As we review, current theories predict that children should struggle to learn polysemous words. Yet recent research shows that young children readily learn multiple meanings for words and represent them in ways that are qualitatively similar to adults. Moreover, polysemy may facilitate word learning by allowing children to use their knowledge of familiar meanings of a word to learn its other meanings. These findings motivate a new perspective on word learning that recognizes polysemy as a fundamental feature of language instead of treating it as an outlying case.