Susceptible to means being prone to or vulnerable to something. There are several other words that can be used in place of susceptible to, including:
1. Prone to: similar in meaning, it indicates that one is likely to be affected by something.
2. Vulnerable to: denotes a state of being easily harmed or hurt by something.
3. Predisposed to: suggests a tendency or inclination towards something.
4. Sensitive to: means being easily affected or influenced by something.
5. Apt to: suggests a natural tendency or propensity towards something.
By using any of these synonyms instead of susceptible to, you can add variety and nuance to your writing, making it more engaging and impactful.