摘要：Polysemy reflects the principle of economy of human language: to reduce the number of words thus releasing human’s memory burden. It’s not only a hot topic in L2 vocabulary teaching and learning, but also studied by cognitive linguists. In this article, polysemy is analyzed from the perspective of The Prototype Theory. The word “agent” is taken as an example since its meanings vary from chemical substance, to deputy in business, a deputy program in computer science, and so on. Besides, how these meanings are related is discussed. The analysis is intended to give some implications for the construction of a new definition model for English learners’ dictionaries, as well as for how to teach and learn vocabulary more effectively.
