Synonyms for prevent include:
Avoid
Deter
Stop
Avert
Preclude
On a related note, you can use the adjectives preventive or preventative interchangeably to mean “intended to prevent,” although many style guides recommend using “preventive” because it is more concise and used more frequently, especially in formal writing.
Use QuillBot’s free Paraphraser to help you find the best synonym for “prevent” in your specific context.