prevent definition

1. keep from happening or arising; make impossible
• examples: My sense of tact forbids an honest answer
• examples: Your role in the projects precludes your involvement in the competitive project
2. stop (someone or something) from doing something or being in a certain state
• examples: We must prevent the cancer from spreading
• examples: His snoring kept me from falling asleep
• examples: Keep the child from eating the marbles