The document defines and discusses different techniques for defining terms, concepts, and ideas. It begins by formally defining definition as a mode of paragraph development that answers what something is, what it means, and its key features. The document then discusses different types of definitions, including formal definition using genus and differentia, and extended definition using analogy, metaphor, comparison/contrast, description, analysis, function, etymology, semantic origin, examples, synonyms, and negation. It emphasizes that definition is important for clarifying meaning and avoiding misinterpretation.