1. (

• prevent ,
• forestall ,
• foreclose ,
• preclude ,
• forbid ,

) keep from happening or arising; make impossible; "My sense of tact forbids an honest answer"; "Your role in the projects precludes your involvement in the competitive project" ;

2. (

• prevent ,
• keep ,

) stop (someone or something) from doing something or being in a certain state; "We must prevent the cancer from spreading"; "His snoring kept me from falling asleep"; "Keep the child from eating the marbles" ;