Online dictionary
Google translate is NOT a good tool for language learning. Why? Students use it to write full sentences in another language. They type in the sentence in English and just have to copy the French. That's not how students can practice a foreign language and learn to use it better.
What if students want to look up just one word? Google translate still isn't great. Dictionaries are great for a lot of reasons, one of them is it makes students think about what they really want to say and parts of speech. Google translate doesn't offer those opportunities.
My recommendation is www.wordreference.com Links to an external site.
Here is a video to help understand how to use it.
When looking up a word, there are usually a few options available, which makes students think about the meaning they want to convey and ask if they want to use a verb, noun, adjective, etc. This thinking process is very valuable and can be practiced with word reference.