false positive

noun

plural false positives

: a person or test result that is incorrectly classified as positive (as for the presence of a health condition) because of imperfect testing methods or procedures

A false positive—a test result indicative of disease that isn't actually present—can trigger a chain reaction of worry, further tests, and even unnecessary treatment.

—Harvard Health Letter

The quarantine could be lifted early if the lab confirms that the case was a false positive.

—Kathleen Moore

Perhaps more important, polygraph tests are notoriously unreliable. Scientists are understandably concerned about false positive results …

—Chemical & Engineering News

—often hyphenated when used before another noun

The technology could improve a radiologist's ability to detect breast cancers and it could lower the number of false-positive results …

—Laurie Tarken

compare false negative

Examples of false positive in a Sentence

Recent Examples on the Web

The company’s own estimates claim that false positives — in which the tool wrongly reports that a piece of human writing was created — are 1 in 10,000 and shrinking. — T.m. Brown, CNN Money, 21 Oct. 2026

According to one meta-analysis, roughly 15 percent of MS diagnoses may actually be false positives. — Dylan Scott, Vox, 21 Oct. 2026

But, the researchers say, artificial intelligence struggles with the messy realities of the cosmos, such as stellar flares and the natural pulsations of stars that can trick the algorithms into false positives. — Sharmila Kuthunur, Space.com, 18 Oct. 2026

Isolating a production server might require human approval because a false positive could disrupt the business. — Asaf Wiener, Forbes.com, 16 Oct. 2026

Word History

First Known Use

1912, in the meaning defined above

Rhymes for false positive

• seropositive
• causative
• dispositive
• electropositive

Medical Definition

false positive

noun

: a person or test result that is incorrectly classified as positive (as for the presence of a health condition) because of imperfect testing methods or procedures

Another problem with the test … is that it also produces a number of false positives; that is, a number of neonates with elevated trypsin levels the first time they are tested are found not to have elevated levels on the second test.

—The Journal of the American Medical Association

The urine dipstick test for protein can give false positive results when various pharmacologic agents and gross hematuria are present or when urine pH is high …

—Biff F. Palmer, Scientific American Medicine

—often hyphenated when used before another noun

… false-positive results that led healthy women to have unnecessary surgery.

—Denise Grady, The New York Times

The test can give false-positive readings, however, and it triggers a follow-up colonoscopy in 4% to 10% of cases.

—Marilyn Chase, The Wall Street Journal

compare false negative