# Definer - Word Translator, Ask AI, Dictionary Extension

> Select text to translate, define, or ask AI. A word translator and dictionary extension for webpages, PDFs, and EPUBs.

Canonical page: [https://chrome-stats.com/d/noagjioaihamoljcbelhdlldnmlgnkon](https://chrome-stats.com/d/noagjioaihamoljcbelhdlldnmlgnkon)

## Overview

- **ID:** `noagjioaihamoljcbelhdlldnmlgnkon`
- **Platform:** Chrome
- **Type:** Chrome extension
- **Status:** Available
- **Publisher:** Lumetrium
- **Category:** Tools
- **Users:** 50,000
- **Rating:** 4.77 / 5 (400 ratings)
- **Version:** 1.16.9
- **Last updated:** 2026-07-08
- **First published:** 2021-06-20
- **Size:** 7.13 MB
- **Data as of:** 2026-09-12
- **Store listing:** [Chrome Web Store](https://chromewebstore.google.com/detail/definer-word-translator-a/noagjioaihamoljcbelhdlldnmlgnkon)
- **Website:** [https://lumetrium.com](https://lumetrium.com/)
- **Privacy policy:** [https://lumetrium.com/legal?service=definer&document=privacy-policy](https://lumetrium.com/legal?service=definer&document=privacy-policy)

## Description

Definer keeps you in the reading flow. Simply select text to trigger an instant popup for definitions or translations. It’s more than a dictionary—AI paraphrasing, AI grammar checking, EPUB and PDF reading, IPA pronunciation, and a Sign Language dictionary are all built in.

You can tailor sources from Wikipedia, DuckDuckGo, and more, and add custom data sources via iframes, turning Definer into a versatile language hub inside your browser.

## Rankings

- #3,273 — Overall
- #4 — dictionary
- #5 — define
- #7 — definition
- #8 — ai paraphrase online
- #8 — paraphrase online

## Permissions and access

### Permissions

- `contextMenus`
- `storage`
- `unlimitedStorage`
- `tabs`
- `declarativeNetRequest`
- `identity`
- `offscreen`
- `scripting`

### Host permissions

- `*://*/*`

### Content script matches

- `<all_urls>`
- `*`

## Safety

- **Risk impact:** High risk impact
- **Risk likelihood:** Very low risk likelihood

### Analysis details

- Grants access to browser tabs, which can be used to track user browsing habits and history, presenting a privacy concern.
- This extension has low user count. Unpopular extensions may not be stable or safe.

> Some risk analysis details are omitted from this free response. [Upgrade to view the full analysis](https://chrome-stats.com/pricing).

## Review summary

Users repeatedly praise Definer for its convenience, fast one-click lookups, AI-assisted explanations, and a highly customizable, feature-rich interface. The popup design lets them stay on the current page while exploring meanings, which is highly valued for language learning and reading. Overall sentiment is very positive, highlighting speed, versatility, and seamless access to multiple sources.

### Pros

- Extremely convenient with one-click word lookup that eliminates tab switching.
- Intuitive, smooth UI and a feature-rich, highly customizable extension.
- AI-powered explanations and translations, plus the ability to connect to your own AI API.
- Supports multiple sources and quick internet lookups from inside the popup (no leaving the page).
- Very helpful for language learners, aiding vocabulary growth and comprehension across English, Japanese and more.

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Source: [Chrome-Stats](https://chrome-stats.com/d/noagjioaihamoljcbelhdlldnmlgnkon)