John Rumm wrote:
Being dyslexic myself (and knowing many others who are) I can reassure
you that speaking incomprehensible ******** is not a well known trait of
dyslexia. Dyslexics lack lexical ability, not oral.
The word you are searching for is "inarticulate".

I think the word is "dense".

Inarticulate people lack oral ability, not logical.

Owain