DictionaryTip extension shows the meaning of the selected phrase in a tooltip on the same page. The main point is "not" to open a new tab or window for looking definitions when you are seriously reading an article. It's a great multi-lingual learning tool.

This avoids the following steps involved in looking a meaning for a word (open a new window, type in the dictionary url, type or copy the word in a lookup/search box and finally click the button Search).

Just double-click on a word to get the meaning from your favourite website on the same page. You can also select a word(phrase), right click and click on 'View Definition' (or) press Ctrl + Shift + K (or any key of your choice) to get its meaning.