Here is another list featuring some very good Chrome extensions for teachers:
1- Auto Translate
This extension allows you to translate words, and sentence by just selecting them. It is powered by Google Translate technologies.
2- Bubble Translate
Translate a selection of text inside any website and view the result without leaving the page.
3- Chrome Dictionary Lite
Powered by Google Translate, Chrome Dictionary Lite lets you to translate the words on your current page.
This extension adds a Google Dictionary button to the context menu when you select a word and right-click.
5- Dictionary Lookup
Allows you to look up definitions (from Wiktionary) of words and phrases (English only) in a clean inline box.
Just double-click on a word and get its meaning, and you can also select the word and press the shortcuts to see the definitions.
7- Google Dictionary
This is available for you to translate foreign words of 11 languages (such as Chinese, English, Italian, etc.) to your language of choice.
8- Inline Search & Lookup
This extension gets definitions from search engines (such as Google), online dictionaries (such as Wiktionary) or encyclopedias (such as Wikipedia), and you can also add your own sources.
it is available for you to look up words in Google (English) Dictionary and/or Google Realtime Search
10- Dynamic Language Tools
This is a Google Chrome Extension which can translate entire webpages to your own language or language of your choice.
11- Right Click and Translate
This is a free Google Chrome Extension which can translate texts on web pages. Right Click and Translate extension is easy to use.
12- Google Translate
Google Translate can translate whole Web Pages into your own language or language of your choice which one simple click