undetected

adjective

un·​de·​tect·​ed ˌən-di-ˈtek-təd 

-dē-

: not observed, noticed, or detected

an undetected flaw/error

an undetected illness

These rare mistakes are subtle and may go undetected for months and even years.

—Mario Salvadori

Examples of undetected in a Sentence

Recent Examples on the Web

Some oil companies have developed new tactics to enable their tankers to pass undetected through the waterway. — Tim Lister, CNN Money, 23 Aug. 2026

Because intense physical activity places additional stress on the heart, undetected heart conditions can become dangerous during sports, the American Heart Association (AHA) told Fox News Digital. — Teresa Mull, FOXNews.com, 22 Aug. 2026

In December 2015, when Eva Benefield was just 14 years old, her mother, Renee Benefield, died suddenly from an undetected congenital heart defect. — Janelle Griffith, PEOPLE, 21 Aug. 2026

Yet the virus spread undetected for a month because researchers were unable to get permission from a rigid bureaucracy to test the swabs that would have helped identify it. — Jennifer Pahlka, Foreign Affairs, 18 Aug. 2026

Word History

First Known Use

circa 1602, in the meaning defined above

Rhymes for undetected

• disaffected
• disconnected
• disinfected
• interjected
• intersected
• misdirected
• preselected
• recollected
• reconnected
• redirected
• reelected
• resurrected