밤새 덕질했어

The line, explained

It is morning, your eyes are dry, and your phone is at two percent. Why? You were watching fancams, translating comments, and organizing photocards until dawn. In Korean, there is one perfect word for all of that: 덕질. And this line, 밤새 덕질했어, I was fangirling all night, is the proud, slightly sleepy confession you might post on a fan account the next day.

밤새 means all night. It comes from 밤 (night) and 새, short for 사이, meaning between or throughout. So it is literally throughout the night. You will hear it in lyrics about crying all night or dancing all night, and in everyday complaints like 밤새 못 잤어, I couldn't sleep all night. Like other time words, it comes at the start.

덕질 comes from 덕후, the Korean version of the Japanese word otaku, meaning a superfan or geek. Add 질, a suffix for a repeated activity, and you get 덕질: all the things fans do. Streaming music videos, voting for awards, buying albums, making edits, rewatching variety clips. 덕후 used to be a little teasing, but fans now wear it proudly, and idols use it about their own hobbies.

To turn 덕질 into a verb, add 하다, to do. That is the beauty of Korean: tons of nouns become verbs this way. 덕질하다 means to do fan activities. In the past tense, 하다 becomes 했어, so 덕질했어 means I did fan stuff. In speech the ㅈ after ㄱ tenses up, so it sounds like deok-jjil-hae-sseo. Romanization keeps the spelling, but your ear will hear the double sound.

Fans also say 입덕, entering a fandom, and 탈덕, leaving one. If you have just fallen hard for a new group, you can say 입덕했어, I've become a fan. Try swapping the activity in this line: 밤새 정주행했어 means I binge-watched all night, and 밤새 게임했어 means I gamed all night. Same 했어, different hobby. No apology needed. Your fandom friends will understand.