Some translations in Odoo can sometimes be incorrect which can be confusing. For example, for one of the options on the website, "signed in" is translated into "arrivée" (arrived). It doesn't make any sense...  

So what can you do ? The translations are handled through Transifex and you can suggest a new translation ! Be aware your suggestions, if approved, will be applied to all databases. 

Here is how:

1.Create an account on https://www.transifex.com/signin/. You can sign in with your GitHub account. Choose your language. 

2.Install the module transifex on the DB. It makes things easier. 

3. Once you have identified the wrong translation, find the translated term in Settings / Translation / Translated Terms. You can quickly access it directly from “Technical Translation” from the debug menu. 

4. Click on "contribute".

5. You'll be redirected to the transifex website. Login and select the language (the one you wish to correct).

6. Edit the translated value and save ! Congrats ! 

What's going to happen? If your translation is the first one in "history", it'll be pushed during the next weekly update. It can happen that the translation is locked (apparently it's mostly for Dutch). In this case you should go to "comments" and open an issue. 

If you want more info: https://github.com/odoo/odoo/wiki/Translations