The document discusses various types of definitions that can be used to reduce ambiguity and vagueness in arguments, including: ostensive definitions, which involve directly pointing out the thing being defined; verbal extensional definitions, which list examples of members of the set; intensional definitions, which outline the properties of members; lexical definitions from dictionaries; stipulative definitions for new terms; precising definitions to clarify vague terms; theoretical definitions based on a particular theory; and operational definitions that provide instructions for determining if something fits the definition. It also discusses ambiguity, vagueness, emotive or persuasive definitions, and gives examples and homework assignments related to defining terms clearly.