Susceptibility

Noun

1. The condition of being susceptible; vulnerability.
2. emotional sensitivity.
3. Being vulnerable to a treatment (usually an antibiotic or antifungal); also, the degree of such vulnerability (i.e., weak, moderate, or strong).

   "Derived terms: susceptibility testing"

4. electric susceptibility, a measure of how easily a dielectric polarizes in response to an external electric field (compare permittivity).