Definition
Something undiscoverable is impossible to find or become aware of. It's like a hidden treasure buried so deep that no map can lead you to it, or a secret so well-guarded that no amount of questioning can reveal it. Undiscoverable things might exist, but they are beyond our reach, hidden by physical or conceptual barriers. Consider the dark side of the moon for early astronomers; it was undiscoverable until space exploration made it possible to see it. It implies a permanent or near-permanent state of being concealed.