LessTabs is a handy browser add-on that lets you highlight a word or a phrase and quickly see its definition, explanation and translation without having to open new browser tabs and manually browsing Wikipedia, thesaurus sources, or other reference providers.
LessTabs is compatible with all the three most popular web browsers of our days: Mozilla Firefox, Internet Explorer, and Google Chrome.
It is easy to install and to use, as it only requires you to highlight the words or phrases that interest you and a pop-up window will be instantly opened to provide you with the needed information.
Besides the Wikipedia entry for the selected words, LessTabs also provides translations between various languages using the reliable Microsoft Bing’s translation service. As for the thesaurus, the WordNet lexical database for the English language is used.
To sum it all up, LessTabs is a really handy add-on that can prove really useful in a lot of situations. Since it’s also free, it gets my recommendation as well.