It stopped working for a while, and wouldn't be able to define the most common words (or could define them once and then stop working after). Fixed itself when I reinstalled the extension. Great add-on otherwise.

LA VERDAD ES LA MAS GUSTOSA exquisita prosa

Très bonne extension, assez rapide en plus.
Deux petits bémols : on ne peut pas prendre plusieurs mots à la fois, ce qui empêche d'obtenir la définition d'expressions par exemple, et il y a un léger problème de compatibilité pour les mots ressemblant trop à l'anglais.
Pour pallier à ce second problème, il serait judicieux de mettre le mot tout seul dans la recherche, sans "define" devant. (Pour ceux qui ne savent pas, l'extension lance une recherche Google au moment du double-click, "define [mot sélectionné]".)

it doesn't have a large dictionary, and that's the only complain.

These type of extensions I consider essential and this one, does the job.

nul

Works great!

excellent

Love this add-on. For anybody reading this that has issues, one thing I have found is that

THIS ADD-ON STOPS WORKING WHEN YOU'RE ON A VPN.

So if you have disabled/enabled, removed/downloaded, changed settings, etc. trying to figure out why it isn't working, that is one possibility. I can't verify if this is true for all VPN services, just some.

I do love this addon, though I wish it had more options, like to check something I wrote myself it it means the same I think or even make it show it's own search bar on addon icon click as I believe it is more convenient then getting new tab and googling it.
Still, can't recommend it enough

This was a decent Dictionary but just quit working. Not as much info like the others unless you went off page.

It has stopped working since yesterday, the last straw for me to ditch Firefox I guess