2026 GMAS 5th Grade ELA Complete Practice Test

Knowing where to find definitions of key words in a text helps readers understand unfamiliar terms without interrupting their reading. A glossary is exactly that—a small dictionary of terms and their definitions tucked at the end of a book. It’s designed to quickly explain words that appear in the text, especially in nonfiction or technical material.

An index, on the other hand, is like a map of topics with page numbers to help you locate information, not to define words. An appendix is material added at the end that provides extra information such as charts or background details, and while some books include a glossary there, the main purpose of an appendix isn’t to define terms. Idioms aren’t a section of the book at all; they’re phrases whose meanings aren’t literal.

So the term that describes a small dictionary of key words and definitions at the end is glossary.