brain rot

Meaning

1. The supposed decline of a mind fed too much low-effort content.
2. The content itself. See every other entry on this page.

“While England endeavors to cure the potato-rot, will not any endeavor to cure the brain-rot, which prevails so much more widely and fatally?” Henry David Thoreau, Walden, 1854.

Where it came from

First recorded in Walden, where Thoreau complained that people preferred simple ideas to hard ones. Oxford named it Word of the Year 170 years later.