This book examines the nature of the interface between word meaning and syntax, one of the most controversial and elusive issues in contemporary linguistics. It approaches the interface from both sides of the relation, and surveys a range of views on the mapping between them, with an emphasis on lexical approaches to argument structure. Stephen Wechsler begins by analysing the fundamental problem of word meaning, with discussions of vagueness and polysemy, complemented with a look at the roles of world knowledge and normative aspects of word meaning. He then surveys the argument-taking properties of verbs and other predicators, and presents key theories of lexical semantic structure. Later chapters provide a description of formal theories and frameworks for capturing the mapping from word meaning to syntactic structure, as well as arguments in favour of a lexicalist approach to argument structure. The book will interest scholars of theoretical linguistics, particularly in the fields of syntax and lexical semantics, as well as those interested in psycholinguistics and philosophy of language.