Just right-click on the selected text and choose "U-Dictionary...". Before that, you can choose a dictionary option that you want on the U-Dictionary popup (click on the extension's icon to show the popup. You should pin the icon right after installing the extension). And you can also lookup there. U-Dictionary is the top free English dictionary. U-Dictionary offers tens of bilingual dictionaries, includes 10 Indian languages: Hindi, Tamil, Telugu, Marathi, Kannada, Malayalam, Urdu, Punjabi, Bengali, Gujarati, and 12 international languages: Indonesian, Vietnamese, Spanish, Thai, Arabic, French, German, Italian, Japanese, Korean, Malay, and Nepali.