- an online test designed so that humans but not computers are able to pass it, used as a security measure and usually involving a visual-perception task: Site visitors must solve the “distorted text” CAPTCHA before posting comments.
- a computer program that generates such tests.
Origin of CAPTCHA
2000–05; C(ompletely) A(utomated) P(ublic) T(uring) (Test to Tell) C(omputers and) H(umans) A(part)
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for captcha
Called "captcha," it's essentially a test that's easy for a human to complete, but difficult or impossible for a computer to do.The ESPN Porn Scam
July 22, 2009