undetected

That allowed the team to go undetected as they prepared to break into the palace.

Ultimately, though, trying to unpick the precise reason for why our food and drink costs what it does is very difficult - other factors that influence price can go undetected.

Narco-subs have become a popular way to transport drugs as they can go largely undetected, and can be sunk after delivery.

It is the architectural equivalent of a stealth airplane, meant to fly undetected—not so much a building as an anti-building.

"They're polite, but they want to catch the traitors, and the traitors want to remain undetected, and both parties are excellent at what they do."