Abstract
This chapter reviews evidence of how children discover and extend word meanings in the moment and how they retain and recognize meanings over time. Children need to understand the meanings of words both to comprehend what others are saying and to successfully communicate their own ideas, needs, wants, and feelings. Young children and adults are sensitive to iconicity, or the correspondence between word sounds and meanings, for example looking longer at a pointy shape when hearing a word like “kiki” or at a round shape when hearing a word like “bouba”. In addition, a number of word learning constraints may reduce the number of meanings under consideration. Across development, children acquire word learning biases leading them to attend to relevant information when learning the names for novel nouns. In addition to learning about solid objects like “cup”, children also learn about nonsolid substances like “yogurt”.