Is 'dumb' offensive AND does it mean someone momentarily doesn't know something or that they can't learn something?

I just got out of a long debate over the meaning of dumb.
1) Is 'dumb' insulting: at all or in context?
2) Does it mean a person doesn't know something, but could learn it, OR that they can't learn something (or maybe just really unlikely to learn it)

The 2 native speakers of English disagreed on both questions

This guy was a university tutor and calling his students dumb as they didn't know a simple concept that 10yr olds learn.
My friend and I said it can be offensive if he were to call a student dumb. He disagreed as he believes dumb is the same as 'uneducated (on a topic)'.


What Girls Said 1

  • Dumb also means the inability to communicate; a mute. It could also mean dazed (incoherent, confused, dull, lack of expression for example ) historically, you wouldn't call someone dumb to imply they are stupid.. you'd call them a fool instead.


What Guys Said 2

  • Can be both of course since both can be true, Not everyone finds it offensive while some do. Some people dont ever change and continue to live with the same old "stupid" mindset while others grow. I dont think the word itself is what defines it, but what people choose to do with it.

    • Cause of update. Certainly sound like he implied that the class or his students was as dumb or dumber than a 10year old. Which yeah kind of an insult that no doubt, supposed to be too.

    • He said its not offensive as he didn't mean they can't learn it, just they should and dont. That wasn't the view of the rest of us when he said it

    • He was just trying to recover or excuse it away cause know he said something he shouldn't

  • Depends on context. If you are saying someone is stupid, it is not that offensive, but remember that it is the intention behind the words that can cause the real hurt.

    If you are using it to describe someone who is non-verbal, it is extremely offensive.