Online Etymology Dictionary

The Online Etymology Dictionary (etymonline) explains the origin and history of English words, phrases and idioms, aimed at readers looking for quick, reliable accounts of where words come from. It was created in 2001 by Douglas Harper, who continues the project, with the etymonline domain name dating from 2003; Talia Felix, an independent researcher, has been associate editor since 2021. The dictionary describes its entries as explanations of what words meant and how they sounded 600 or 2,000 years ago, rather than definitions.

The site offers a browsable A-to-Z index, a forum, mobile apps, and a Premium tier alongside Patreon and PayPal donation options and merchandise. A sponsored article ad spot is available, priced through negotiation, and its ads.txt file lists 44 ad system lines, made up of 2 direct entries and 42 reseller entries.