definition of autistic
auÂ·tism. n. A pervasive developmental disorder characterized by severe deficits in social interaction and communication, by an extremely limited range of activities and interests, and often by the presence of repetitive, stereotyped behaviors.auâ²tist n. auÂ·tisâ²tic (-tÄ­k) adj. & n.auÂ·tisâ²tiÂ·calÂ·ly adv.uÂ·tism. n. A pervasive developmental disorder characterized by severe deficits in social interaction and communication, by an extremely limited range of activities and interests, and often by the presence of repetitive, stereotyped behaviors. auâ²tist n.