You can use a lernu! dictionary from the window on the top right. Open the dictionary by clicking on the small green arrow. If you don't see the dictionary, perhaps you hid the whole right-hand side of the page. To make it visible again, click on the small blue arrow on the far right side of the main menu.

Now you can begin:

1. In the drop-down menu, choose the dictionary you want.
2. Choose a dictionary from the drop-down menu. In the empty field, type in a word in the language whose dictionary you selected and click "Ek!". When searching for words, you can use an asterisk; * - for zero or more characters following the letters you have typed so far, and ? for one character. For example, if you write "bon*", the dictionary will offer you words like "bona", "bono", "bone", "bonanima", "bondeziri", etc. If you write "bon?", the dictionary will find the words "bona", "bone", and "bono". You can also use the asterisk in the middle of a word.
3. If you don't understand one of the words in the translation/clarification, you can click that to receive further clarifications.
4. If the word you want doesn't exist in the chosen dictionary, try again in another dictionary, and/or send a comment to us about it (the comment link is at the bottom of every page)

However, you can use the dictionaries for any of the Esperanto texts in the webpage. Just click a word you don't know, and a clarification will appear in the dictionary window and in a floating window next to the word you clicked on.