captcha

noun

capt·​cha ˈkap-chə 

variants or CAPTCHA

: a test to prevent spamming software from accessing a website by requiring visitors to the site to solve a simple puzzle (typically by reading and transcribing a series of numbers or letters from a distorted image) in order to gain access

The point of the CAPTCHA is that reading those swirly letters is something that computers aren't very good at. If you can read them, you're probably not a piece of software run by a spammer.

—Lev Grossman

Examples of captcha in a Sentence

Recent Examples on the Web

The hack placed a fake CAPTCHA test on the landing page for iClicker.com, according to BleepingComputer. —Michael Kan, PC Magazine, 12 May 2025

The first is that everyday CAPTCHA checks are just harmless speed bumps. —Kurt Knutsson, FOXNews.com, 12 May 2025

These included social engineering scams using a fake CAPTCHA test as well as legitimate tooling, including VoIP and Adobe software, along with messaging clients. —Davey Winder, Forbes, 17 Mar. 2025

And, dear reader, the next step after this fake CAPTCHA was to enter Microsoft account credentials, the email address of which was already filled out. —Davey Winder, Forbes.com, 14 Apr. 2025

Word History

Etymology

Completely Automatic Public Turing test to tell Computers and Humans Apart (with deliberate pun on capture entry 1)

First Known Use

2001, in the meaning defined above