undetected
adjectiveUK /ˌʌndɪˈtektɪd/
US /ˌʌndɪˈtektɪd/
Not noticed or found by anyone.
The cat slipped into the kitchen undetected.
OTHER MEANINGS
2. Not discovered by a machine or test.
The flaw in the metal went undetected for years.
3. Able to pass without being caught.
The spy moved through the building undetected.
4. Not recognized as a problem or illness.
Her hearing loss stayed undetected until she was five.