susceptibility

Short definition from Wiktionary

Noun

1. 1
   The condition of being susceptible; vulnerability.
2. 2
   emotional sensitivity.
3. 3
   Being vulnerable to a treatment (usually an antibiotic or antifungal); also, the degree of such vulnerability (i.e., weak, moderate, or strong).
4. 4
   electric susceptibility, a measure of how easily a dielectric polarizes in response to an external electric field (compare permittivity).