Quick Dictionary от Trần Xuân Thắng

Quick Dictionary helps you quickly translate any selected text in the web to any languages with Wiktionary. With the help of Wiktionary, you can fully understand any meanings of words you want to look up, with IPA pronunciation and text-to-speech support. If you are looking up the meaning of paragraph, or a word that are not available at Wiktionary, it will try to look it up on Google Translate.

Instruction:
1. Select a word/paragraph with drag-and-drop/double click/triple click...
2. Click on the "browser action" button of the extension OR use the hotkey "Ctrl+Shift+Q".
3. The word/paragraph meanings will show up.
Alternatively, you can just open the extension popup, and type in the textbox and search from there.

Some newly added feature:
* A "quick button" that shows right above the selected text, click on it will open a popup (new window).
* You can select up to 2 language version of Wiktionary.
(Gfycat of 2 above features: https://gfycat.com/YellowishWastefulDove)


Notes:
This extension can't translate selected text of Firefox's important site (such as about:preferences or addons.mozilla.org).
The speed of the extension depends on your internet speed to Wiktionary.
The extension won't work when you are not connected to the internet.