Zotero Plugins Atlas
Plugins / Reading & PDFs

Defn

by aadi219 · github.com/aadi219/defn

Lets you mark a definition in a PDF, then underlines every other occurrence of that term so hovering shows the definition.

Defn has Atlas grade A (recommended) because every code check came out low. It works with Zotero 8–9, not the current Zotero 10. Last checked 6 Nov 2026.

Reading & PDFs
View source
Downloads a .xpi file (0.07 MB). In Zotero, open Tools → Plugins and install it from the file.
In useAn estimate of how many copies of Zotero have it: Zotero downloads each new version once for every copy that has the plugin, so we count the downloads of its most-downloaded recent release. Rounded. Plugins that update from outside GitHub count low.
40
DownloadsAll-time downloads of its release files from GitHub, counting every update. Installs from elsewhere aren't counted.
40
ReleasesVersions published on GitHub. Everyone who has the plugin downloads each one again, which adds up in Downloads.
1
StarsPeople who starred the repository on GitHub: a rough measure of interest.
0
ContributorsPeople who have committed code to the repository.
1
LicenceThe licence the code is published under, as GitHub reports it.
MIT
A
Atlas gradeRecommended
because every code check came out low
Applies to v0.1.0, released 7 Oct 2026Code checked · not yet tested in a live Zotero
Doesn't work with the current Zotero (10)Works with Zotero 8, 9.
What we found in the codeSets the gradeThe worst finding in these three areas sets the grade.
Code transparencyReadable code; not yet checked against the published sourceThe developer uploaded the release file from the aadi219 account. We haven't yet checked whether this file matches the public source code.UnknownWe couldn't check this yet.
Updates
Updates come from this project's GitHub repositoryThe update address offers this version
Where your data goesNo web requests foundLowLow concern: normal for plugins that do this job. Listed so you know.
No further detail for this area yet.
Powerful capabilitiesWorks with files on your computerLowLow concern: normal for plugins that do this job. Listed so you know.
Low concern (1)
Works with files on your computer
Before you installShown, not gradedFacts to help you decide. They don't change the grade.
Works withZotero 8, 9 · not 10, 11 betaDoesn't work with the current Zotero (10)MediumMedium concern: worth reading before you install. One medium finding makes the grade B.
Zotero 8 ✓ worksZotero 9 ✓ worksZotero 10 ✗ doesn't workZotero 11 beta ✗ doesn't work
What you'll needZotero 8, 9Detected automatically from its code
No further detail for this area yet.
MaintenanceActive · last release 7 Oct 20261 contributor
No further detail for this area yet.
LanguagesDocumentation in EnglishInterface language not declared
No further detail for this area yet.
We report what we found in the code. Open any area for the evidence.How we gradeReport a problem

What it does

Written by AI from the README

Lets you mark a definition in a PDF, then underlines every other occurrence of that term so hovering shows the definition. Offers pinned definitions in a side panel and a searchable glossary. Also runs as a web app.

Textbooks and papers reuse terms defined chapters earlier, and finding the definition means scrolling or searching. Definitions are also saved as Zotero highlights. Its developer notes it was built with AI assistance.

What you'll need

Detected automatically
  • Zotero 8, 9Not working with Zotero 10

Where your data goes

We found: no web requests found.

Other plugins that do this

Matched on what they do

For the same job, work with Zotero 10 and graded A or better. Closest match first.

  • A+
    Science Lens — Wikipedia definitions

    Select a word or phrase in the PDF reader and click Define · Wikipedia to see a short English Wikipedia definition with a thumbnail in a reader panel.

    Matches “term definition popup” · 55 downloads · Active · Zotero 10
    Works with Zotero 10
Compare all 2 side by side
How we pick these

By how closely what they do matches this plugin, using descriptions and the phrases people search with. Copies and forks of this plugin are listed under Forks and copies instead. No plugin pays to appear here.

Forks and copies

No forks listed.

The developer's response

The developer hasn't responded. Developers can reply here, and their reply sits next to our findings.I'm the developer

Ratings and reviews

What people who use it say. This is separate from the grade, which is what the code does, and never changes it.

No ratings yet.

Write a review
Your rating of Defn v0.1.0

Your review is public, under the name you give, and published with the directory's data under CC BY 4.0. Links are removed. We never store your IP address: a scrambled code made from it is kept for 30 days to catch fake reviews. Every review is checked before it's published; how fake ones are spotted isn't published, so it can't be gamed.

Install Defn
ARecommended
  1. 1Download the plugin fileDownload v0.1.0.xpi · 0.07 MB
  2. 2In Zotero, open Tools › Plugins
  3. 3Click the gear, choose Install Plugin From File… and pick the file
Step-by-step guide with pictures