Autism spectrum disorder is a complex developmental disorder that affects communication, social interaction, and behavior. There are many synonyms for autism spectrum disorder, each describing a different aspect of the disorder. Some of the most common synonyms for autism spectrum disorder include Asperger's syndrome, pervasive developmental disorder, and high-functioning autism. These terms indicate varying levels of severity, with Asperger's syndrome describing a milder form of autism, and pervasive developmental disorder indicating a more severe form. Other synonyms for the autism spectrum disorder include autistic disorder, atypical autism, and childhood disintegrative disorder. All of these terms are used to describe individuals who exhibit any of the symptoms associated with autism spectrum disorder.