susceptibility

The condition of being susceptible; vulnerability.

It has been reported that periparturient cows undergo a period of immunosuppression of various immunological parameters associated with a high susceptibility to uterine and mammary infections […]

emotional sensitivity.

The eyes were large and black, and had the moonlight's melancholy, with that tearful lustre which is the certain sign of keen susceptibility.

Being vulnerable to a treatment (usually an antibiotic or antifungal); also, the degree of such vulnerability (i.e., weak, moderate, or strong).

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