Delulu, Explained: How a K-Pop Fan Tease Landed in the Dictionary

When KiiiKiii held a press showcase for "Delulu Pack" at Yes24 Live Hall in eastern Seoul on Jan. 26, as Korea JoongAng Daily reported, the group put a piece of old fandom slang on the marquee. Delulu is short for "delusional," and Merriam-Webster defines it as "delusional; audaciously self-confident."

In its first fandom sense, as Wikipedia describes it, the word was for fans in a one-sided attachment to a celebrity who hoped to meet them someday. Since then it has moved well beyond stan forums, into TikTok manifesting videos, a speech in Australia's Parliament and two major dictionaries.

What it means

Merriam-Webster lists delulu as an adjective, pronounced dih-LOO-loo. It is a clipped "delusional" with the "-lu-" doubled for expressive effect.

The word has a few shades, depending on who says it and to whom:

• The jab. Merriam-Webster says it began as a mild rebuke of stanning and shipping opinions that came across as irrational, obsessive or ridiculous. Korea JoongAng Daily says fans once used it to mock daydreams of dating pop idols.
• The shipping sense. Wikipedia notes it also describes fans who take any interaction between two celebrities as proof they are dating.
• The self-belief sense. Wikipedia's broader definition is believing you can shape your destiny through willpower alone. Teen Vogue puts it as believing in something other people might write off as fantasy or wishful thinking.

It also has spin-offs. Wikipedia lists "solulu" (solution) and "trululu" (truth) as words modeled on delulu. Merriam-Webster records the catchphrases "delulu is the solulu" and "may all your delulu come trululu."

Where it came from

The sources agree on where it started but not on the year.

Wikipedia traces delulu to K-pop internet communities like the OneHallyu Forum, active around 2013 and 2014, where it was often used to mock people with unrealistic hopes of meeting an idol. Merriam-Webster dates it to online K-pop fandom in the early 2010s and adds a caveat: it may have been coined earlier, somewhere else. Korea JoongAng Daily places it in the mid-2010s, in international K-pop fan communities, aimed at fans who thought a romance with an idol was possible.

Linguist Matthew Veras Barros, citing Know Your Meme, wrote on Medium in September 2023 that the word entered English from the K-pop community around 2014. So the fandom origin is clear, but nobody has pinned down the first use.

The jump to the mainstream came later. Merriam-Webster says delulu spread across social media as a general word for "delusional" in the early 2020s. Wikipedia says it went viral with Gen Z and Gen Alpha on TikTok and Instagram from late 2022, and that the #delulu hashtag had passed five billion TikTok views as of December 2023.

That is also when the meaning turned around. Merriam-Webster says that starting in 2023, young women on TikTok used it to mean confidence that their goals were within reach. The Guardian made a similar point, as recounted in a Korea JoongAng Daily story: a term that started as mockery became a self-affirming meme, with "delulu is the solulu" used to manifest wishes.

The K-pop roots never really went away. The Times reported in 2024, according to Korea JoongAng Daily, that TikTok users were posting photos of BTS member Jimin captioned as their boyfriend, part of a delulu trend passed around playfully in K-pop circles.

By 2025 the word had reached politics. Wikipedia records Australian Prime Minister Anthony Albanese mocking opposition policies in Parliament as "delulu with no solulu." That August, Korea JoongAng Daily relayed a Guardian report that Cambridge had added delulu to its dictionary, along with "skibidi," "tradwife" and "broligarchy."

In the headlines

• Teen Vogue, March 25. In an interview with KiiiKiii, the magazine reported that the group sees delulu as more than escapism. It also reported that "404 (New Era)" was KiiiKiii's first song on the Billboard Global 200, so a group that leans into the word has also reached a global chart.
• Korea JoongAng Daily, Jan. 26. The paper covered KiiiKiii's Seoul showcase for "Delulu Pack," a sign the word has come back to K-pop, this time in an idol group's own title.
• Korea JoongAng Daily, August 2025. The paper's story on Cambridge adding the word asked whether K-pop fandom had just contributed a term to the dictionary. It was a milestone for a word that began as a forum insult.

How to use it (and how not to)

A few lines a fan might actually say:

• "I know it's delulu, but I'm already planning my outfit for the fansign."
• "Delulu is the solulu. I'm entering the ticket lottery anyway."
• "Calling it now, those two are dating. Yes, I'm aware I'm delulu."

On etiquette, the self-mocking, self-affirming version the Guardian describes is the friendly one. Aimed at someone else's dating fantasy or shipping theory, the word carries the mockery and rebuke it started with, according to Korea JoongAng Daily and Merriam-Webster. Saying it about yourself usually goes over better than saying it about someone else.