hallucination is common language for these models at this point which describes a particular type of error where the models make shit up.
it is noticeable that the form of this particular error holds a similar shape to what is casually described as hallucinations, in that there is a generated content that often appears to blend naturally into the rest of the output but is false.
the term hallucination often invokes a caution that this particular type of error may be influential and believable and is particularly dangerous