AALookup

For PDFs and papers

Every unfamiliar word in a paper, explained where it stands.

Preview, Acrobat, a browser, Zotero. Whatever you read PDFs in, point at a word and AALookup opens beside it with the meaning this sentence is using and the full entry from your dictionaries. No copying into a search box, no second window. Scanned pages work too.

No account needed. Your dictionaries stay on your computer.

Google Chrome Real screenshot
A paper in the browser's PDF viewer. The term is explained with the sentence around it.
ablation A paper in the browser's PDF viewer. The term is explained with the sentence around it.

What you can do

The meaning in this sentence, not the whole entry

Technical words have everyday senses too. You get the one the paper is using, with the dictionary entry below it when you want more.

Scanned and image PDFs

If the text can't be selected, AALookup reads it from the screen. Old scans, figures and slides work like typed text.

Keep the terms with their context

One tap saves the word with the sentence it came from. When you review it later, you see that sentence, not a bare definition.

Free, no sign-up

How to start

  1. Download and open AALookup

    Choose the download for your system. The current version and installer size are listed below.

  2. Let it see your screen

    On a Mac, allow Accessibility so it can read the word under your pointer, and Screen Recording for text in games and images. Windows asks for nothing.

  3. Point at a word

    Three-finger tap on a Mac, or press your shortcut on Windows. The meaning appears next to the word.

What users say

I'm a Mac user, and the trackpad gesture alone made me download it. Lookups are fast, and it combines the strengths of dictionaries and AI. The built-in three-finger Look Up often gets the range of a Chinese word wrong; AALookup is spot-on in English and nearly always right in Chinese. Genuinely smooth.

@w***0 FreeMdict forum 2026-08

It's not just fast, it's that you can look things up anywhere. And the interface is modern; it feels like my dictionary app jumped from an antique straight into the present.

@w***t FreeMdict forum 2026-08

Common questions

Which PDF readers work?

All of them. AALookup reads the word under your pointer, so the reader doesn't matter. On macOS, allow Accessibility, and Screen Recording for scanned pages. Windows needs nothing extra.

Does it handle phrases and technical terms?

Yes. Point at one word and the explanation covers the term it belongs to, such as an ablation study or an event horizon.

Can I use my own dictionaries?

Yes. Import a folder of MDict dictionaries once, and specialist dictionaries work like any other.

Is it free?

Yes. Dictionary lookups are free, offline and unlimited. AI explanations come with a free trial.

Get AALookup

Free download

Local dictionaries work offline and without limits. AI explanations come with a free trial.

Checking the latest release…