Non verbal According to schools or at least the ones where I'm from is where they don't speak at all that is what Ne defines it as.

Verbal means speaking, it doesn’t matter if echolalia.
Non-verbal means unable to speak, but still doesn’t mean incapable of speaking.

I consider my son verbal but limited. He will express his wants and needs. But you won't get a full back and forth conversation. I will say something like what movie do you want tonight? He will tell me the title and then go on about some other movies and that's it. I'm grateful because he didn't start speaking until he was 4 almost 5. So any conversation is a blessing.

My daughter was nonverbal in that she didn't speak at all. We had to learn sign language as a family and she had a talk tech device to communicate for her and graduated to PECs. I would be careful when using that term because there are families who do have children who do not speak at all...utter no words or sounds.

I and my sons neurologist consider my son as nonverbal ...he can babble, and says mamamama, but with absalutlely no meaning to it...its just a part of his babble ....so for me his being nonverbal is having that communication barrier between us where we use gestures and sign and pecs...