[huntie]

Firefox's spellchecking is just generally awful, even for English. It fails to recognize even basic words such as 'surveil' with the closest suggestion being 'survive'. I've found several other words I wanted to use that weren't found too. I have spellcheck off by default but when I write something long I do a quick check at the end so I don't normally notice this.

Firefox is by far my least favorite piece of software that I regularly use and I've considered throwing my computer out the window because of it.

[orf]

I think you need to install a new or different dictionary. It’s dumb, but that’s how it works - spellcheck dictionaries are provided on the Mozilla extension store. You could try a new one.

[huntie]

There is something seriously wrong with Firefox if the default spellcheck dictionary is so bad that I might need to install a different one, especially for the English language. Hell they should just be able to merge theirs with Chromium's. Regardless, as I said I don't normally use spellcheck and I trust my own judgement over the computer's so it isn't a big deal for me.