Here are some examples:
* Cryptococcus: A genus of fungi that can cause infections, particularly in people with weakened immune systems.
* Cryptosporidium: A genus of parasitic protozoa that can cause diarrhea.
* Cryptogenic: Of unknown origin or cause, often used to describe diseases or conditions.
* Cryptomenorrhea: Menstrual flow that is concealed, often due to a blockage in the vaginal canal.
Therefore, the combining form "crypto-" indicates something that is not easily visible or is obscured in some way.