What part of speech is the word saline?

"Saline" can be two parts of speech depending on its usage:

* Adjective: Describing something that contains salt, like "saline solution".

* Noun: Referring to a salt solution, especially one used in medicine, like "the nurse administered saline".

Let me know if you have a specific sentence in mind, and I can tell you which part of speech it is in that context.