Google Dictionary is very popular extension it is used for define some words or text. when we install this extension and mark some text it will show definition of text in hover which indexed in Google history. You can try this chrome extension its 100% free and very helpful extension it ill also increase your social knowledge.
Get this Extension here
With this extension, you can: 1) Double-click any word to view its definition in a small pop-up bubble. 2) View the complete definition of any word or phrase using the toolbar dictionary. Foreign words are automatically translated to your language of choice. IMPORTANT: The pop-up bubble will not work in tabs that were open prior to installation; such tabs must be refreshed. Also, note that all extensions are disabled on Chrome Web Store pages (including this page).
Supported dictionaries: – Chinese (Simplified) – Chinese (Traditional) – Czech – Dutch – English – French – German – Italian – Korean – Portuguese – Russian – Spanish