activation phrase

noun1

1. •
   (Internet, humorous) A phrase that triggers a person into doing a specific action upon hearing it. Used to joke about niche internet quotes or memes that may trigger an immediate reaction of some sort. Also known as a trigger phrase. Associated with the idea of a "Sleeper Agent"

   • ...Over the following years, the term became increasingly popularized and was particularly used to respond to tweets that featured slang overload. — 2011