The term ‘allistic’ is a synonym for ‘non-autistic’. The term ‘neurotypical’ is used to describe individuals with typical neurological development or functioning. Notably, this term is not an exact synonym of ‘non-autistic’; it is possible to be non-autistic but not neurotypical (e.g., if you have ADHD; see further discussion in Results and Discussion).

Autism-related language preferences of English-speaking individuals across the globe: A mixed methods investigation — University of Birmingham

Allistic: A non-autistic person who can still have other mental conditions, such as depression or ADHD.

salti the Late Diagnosed Autistic on Tumblr

Allism is the antonym of autism. An allistic person is someone who is not autistic.

Neurotypical (or NT for short) is often used synonymously with allistic by many people. However, this is incorrect: while an allistic person can, by definition, never be autistic they can still be neurodivergent in other ways. (For example: someone who isn’t autistic but is ADHD is both allistic and neurodivergent)

Allism – ActuallyAutistic Wiki