Where in a technical manual would you find the definition of a term you do not understand?

The correct choice is to consult the glossary of a technical manual when seeking the definition of a term that is not understood. The glossary is specifically designed to provide definitions and explanations of terminology used within the manual, often organized in alphabetical order for ease of access. It serves as a quick reference for readers to familiarize themselves with specialized language or jargon that may not be commonly known or understood.

In contrast, the table of contents is meant to outline the structure of the manual, listing the chapters or sections but without detailed definitions. The introduction section typically provides an overview and background information on the subject of the manual, but it does not focus on defining specific terms. The index, while useful for finding specific topics or terms within the manual, does not provide definitions; rather, it points to the pages where certain terms can be found. Thus, the glossary is the most appropriate and direct source for definitions.