“Brain rot,” though first recorded in Henry David Thoreau’s Walden, has emerged as a defining word of online, and especially meme, culture. It is used to refer to memes or content with little to no, and in some cases, deleterious, value.

The outfit defines brain rot as the “supposed deterioration of a person’s mental or intellectual state, especially viewed as a result of overconsumption of material (now particularly online content) considered to be trivial or unchallenging. Also: something characterized as likely to lead to such deterioration.”

The word was decided upon based on a combination of data analysis by OUP lexicographers and public input. They noted a 250% increase in frequency per million words from 2023 to 2024.

President of Oxford Languages Casper Grathwohl said the growing trend in OUP’s word of the year is a growing centering on the internet. He pointed to last year’s example of “rizz,” which he said was “an interesting example of how language is increasingly formed, shaped, and shared within online communities.”

“‘Brain rot’ speaks to one of the perceived dangers of virtual life, and how we are using our free time,” Grathwohl said. “It feels like a rightful next chapter in the cultural conversation about humanity and technology. It’s not surprising that so many voters embraced the term, endorsing it as our choice this year.”

Brain rot triumphed over five other finalists — demure, slop, dynamic pricing, romantasy, and lore — nearly all of which came to prominence due to their use in online culture.

Not everyone was in agreement — Collins Dictionary selected “brat” as its word of the year, a word referenced in the entry for “demure.”