APA Dictionary of Psychology

a distortion between words and their culturally accepted meanings that is characteristic of the thought disorder of individuals with schizophrenia. It includes semantic dissolution, marked by a complete loss of meaning and the ability to communicate; semantic dispersion, in which meaning and the correct use of syntax are lost or reduced; semantic distortion, in which meaning may be transferred to neologisms; and semantic halo, marked by coherent but vague and ambiguous language.