Every dense document comes with its own private vocabulary — acronyms nobody expands, jargon that assumes you already know it, product and project names that mean nothing until someone explains them. Building a glossary by hand is tedious, which is why almost nobody does it. Generating one with AI takes seconds, and done right, it gives you a definition you can actually trust because it's tied to where the term appears in the text. Here's how to generate a glossary from a document, and what separates a useful one from a plausible-sounding mess.
Why a glossary is worth generating
A good glossary does three quiet but valuable things. It onboards new readers fast — no more stopping every paragraph to ask "what does that stand for." It surfaces the assumed knowledge a document was written on top of. And it's a reference you return to, so you're not re-deriving the same acronym on page 40 that first appeared on page 3.
The catch is trust. An AI that invents definitions is worse than no glossary — a confident, wrong definition of a key term propagates through everyone who reads it. So the goal isn't just "extract terms," it's "extract terms and define them from the document, with a way to check."
How to generate a glossary from a document
1. Open the document
Point your tool at the document — a report, a contract, a research paper, a wiki page. With a browser reader like Sidenote, you open the document where it already lives and build the glossary from it directly; there's no upload step.
2. Extract the terms
A large language model reads the text and pulls out what a reader is likely to trip on: acronyms, domain jargon, and proper nouns (products, projects, people, systems). The point is to catch the vocabulary the document assumes you already know.
3. Define each term — from the document
This is where quality is made or lost. Sidenote's glossary builder defines each extracted term and cites where it first appears in the text, so the definition is anchored to the document's own usage rather than a generic dictionary meaning that might not match how this document uses the word.
4. Verify and extend
Because each entry cites its first mention, you can jump to the source and confirm the definition fits the context. And for a topic that spans several files, you can build one glossary across a whole Collection — a set of related documents — with each term citing which document it came from.
What a good AI glossary tool does
| Capability | Why it matters |
|---|---|
| Extracts acronyms, jargon, proper nouns | Catches exactly the terms readers stumble on |
| Defines from the document, not a generic source | The definition matches how this document uses the word |
| Cites each term's first mention | You can verify the meaning in context |
| Works across a set of documents | One glossary for a whole topic, not one per file |
| Reads in place, no upload | Build it from the document where it already lives |
Sidenote's Glossary does all of this, and the definitions inherit the same source-grounding as its answers — nothing is invented and left uncited. On the free tier you get a few glossary builds a month; higher tiers and Collections lift that.
Frequently asked questions
Can AI build a glossary from a PDF or wiki page automatically?
Yes. A tool like Sidenote scans the document, extracts the acronyms, jargon and proper nouns, and defines each one with a citation to where it first appears — so you get an automatic glossary you can verify against the source. It works on PDFs (including scanned ones), Confluence and Notion pages, Google Docs, web articles and more.
How do I know the AI's definitions are accurate?
Look for grounding. Sidenote cites each term's first mention in the document and defines it from that usage, and drops claims it can't match to the text. That lets you click through and confirm the definition fits the context, rather than trusting a generic dictionary meaning that may not match how the document uses the word.
Can I make one glossary that spans several documents?
Yes — group the documents into a Collection and build a single glossary across all of them. Each term cites which source document it came from, so a glossary for a whole project or topic stays traceable to the specific file behind every definition.