undetectable

adjective

un·​de·​tect·​able ˌən-di-ˈtek-tə-bəl 

-dē-

: unable to be detected : impossible to discover or notice : not detectable

an almost undetectable change

undetectable traces of poison

Signs of life may be so minimal as to be undetectable by modern instruments …

—Lauren J. Livo

undetectably

ˌən-di-ˈtek-tə-blē 

-dē-

adverb

an undetectably small change

Examples of undetectable in a Sentence

Recent Examples on the Web

At the time, a representative for Botanic Tonics, the company behind Feel Free, told USA TODAY its Feel Free Classic tonic contains only natural leaf kratom, with nearly undetectable levels of 7-OH. — Charles Trepany, USA Today, 21 Aug. 2026

This subtle watermark, undetectable to human readers, alters word patterns and persists through minor edits, with a detection API forthcoming. — Christopher Rim, Forbes.com, 21 Aug. 2026

That means even a clump large enough to play the role of a gravitational lens would be undetectable. — Robert Lea, Space.com, 19 Aug. 2026

Today, Prum takes medication to keep her HIV to undetectable levels in her body, preventing health complications. — Durrie Bouscaren, NPR, 6 Aug. 2026

Word History

First Known Use

1863, in the meaning defined above

Rhymes for undetectable

• collectable
• collectible
• correctable
• delectable
• detectable
• expectable
• injectable
• protectable
• resectable
• respectable
• selectable
• uncollectible