I love this free resource. When I need absolute certainty about what I am looking up, I will go to my beautiful and totally current hardcover American Heritage dictionary, but for a quick check of a word’s meaning or etymology, I run to Dictionary.com. 

The site offers information from multiple dictionaries, so if you look up a word, you can often scroll down a longish page to see what different sources have to say about it.

Although this site is dedicated to English, it is still relevant to foreign-language interests in the sense that so many English words came from other languages. So you can look up “aardvark” and find out that it has a Dutch history, or search for “zebra” and learn about its Portuguese ancestry.

For curious word lovers, Dictionary.com is a lot of fun!