2. a. The systematic process of assessment and planning employed to remediate or prevent a social, educational, or developmental problem: early intervention for at-risk toddlers.
b. An act that alters the course of a disease, injury, or condition by initiating a treatment or performing a procedure or surgery.
c. A planned, often unannounced meeting with a person with a serious personal problem, such as addiction, in order to persuade the person to seek treatment.