The word salinity can mean the relative proportion of salt in a solution. Increasing the salinity of a solution will make it sterile, which is why it is often used in medical procedures.
The noun salinity is derived from the word saline thought to come from the Latin word salinium meaning "salt cellar" and the suffix ity meaning "condition or quality of being." Mixing salt with water makes a solution with high salinity, which has a sterilizing effect when used in medicine. Salinity is also associated with taste and food. You'll want to avoid foods with high salinity if you have high blood pressure.