In effect, the ship was silent and completely undetectable.
Such bodies would be completely undetectable using any techniques of present-day astronomy.
To the rest of the vampire world, she was completely undetectable.
Several torpedoes found their target, confirming that no stealth technology was completely undetectable.
Even though radio waves are invisible and completely undetectable to humans, they have totally changed society.
If Microsoft can come up with a way to detect these rootkits, they're not completely undetectable.
The vessel becomes completely undetectable unless it blocks off a light behind it like a star.
The ship is completely undetectable by all scientific intruments.
Suppose there were a completely undetectable drug that enhanced performance in the 100-meter dash.
It seemed to come and go in waves, sometimes very noticeable, at other times completely undetectable.