IPA: /ˌæd.vɜːrˈtɪə.ri.əl/
KK: /ædˈvɜːrtɪəl/
A type of advertisement that is designed to look like an article or editorial, promoting the views or interests of a company or organization.
The magazine featured an advertorial that discussed the benefits of the new product while looking like a regular article.
Advertorial is a blend of "advertisement" (from Latin "advertere", meaning to turn towards) and "editorial" (from Latin "editorialis", meaning relating to an editor). The word refers to content that is designed to look like an editorial but is actually an advertisement.
Think of an 'advertisement' that is presented in an 'editorial' style — that's what an advertorial is.