1) According to U.S. federal legislation, disabilities involved in understanding or using language, manifested in impaired listening, thinking, talking, reading, writing, or arithmetic skills. Includes perceptual handicaps, brain injury, minimal brain dysfunction, and developmental aphasia. Compare LEARNING DISORDERS.

2) Any of various disorders (as dyslexia or dysgraphia) that interfere with an individual's ability to learn resulting in impaired functioning in verbal language, reasoning, or academic skills (as reading, writing, and mathematics) and are thought to be caused by difficulties in processing and integrating information.