Final answer:
Hygroscopic refers to the ability of refrigerant lubricants to absorb moisture from the environment, which can lead to corrosion and reduced performance. It is important to use lubricants that are designed to be hygroscopic or take steps to prevent moisture from entering the system.
Step-by-step explanation:
When referring to refrigerant lubricants, the term 'hygroscopic' means that the lubricant has the ability to absorb moisture from the surrounding environment.
This can be problematic because moisture in the lubricant can lead to corrosion, damage to the refrigeration system, and reduced performance. In order to prevent these issues, it is important to use lubricants that are specifically designed to be hygroscopic or to implement measures to keep moisture out of the system.