crypto-

Hidden, invisible.

crypto- + crystalline → cryptocrystalline (“whose crystalline nature only becomes apparent at high levels of magnification”)

crypto- + zoology → cryptozoology (“the study of animals whose existence has not been proven”)

Secret.

crypto- + fascist → cryptofascist

crypto- + -lect → cryptolect (“a secret language”)

Relating to cryptography, the study of secret communication.

crypto- + function → cryptofunction

crypto- + variable → cryptovariable

Cryptocurrency.

crypto- + asset → cryptoasset

crypto- + collectible → cryptocollectible