A phrase made by k-pop boyband Seventeen's Jeonghan. It's a word play that consists of a few random korean words that sounds funny (바기바기 차덜 바기 신기방기 뿡뿡방기). This phrase was nominated as k-idol meme of the year award. Several k-pop idols such as Stray Kids, Loona, TXT, Enhypen and more has used this phrase. It even got to be featured in several k-pop reality shows and it is popular among knets.
This word was created by Jeon Jungkook, the youngest member(maknae) of BTS (a boyband from South Korea). The word "Apo! Bangpo!" translates to the short form in Korean for "ARMY forever, Bangtan forever".
(PS: ARMY is BTS's fandom name, and Bangtan sonyeondan is what BTS stands for).
For instance;
ARMY uses "Apo! Bangpo!" among themselves and to towards BTS to show affection. BTS too uses this to express their love towards fans.
Bangtan Sonyeondan, knows as BTS or Bulletproof Boys Scout is a South Korean kpop group under Big Hit Entertainment. They debuted on 13 June 2013. They are known for the music they made and energizing dances. BTS consists of Rap Monster (leader, rapper), Jin (eldest, vocal, visual), Suga (rapper), J-Hope (main dancer, rapper), Jimin (main dancer, vocal), V (vocal) and Jungkook (youngest, main vocal, dancer). Their fanbase is called A.R.M.Y (Adorable Representative Mc of Youth).
Example Girl 1 : OMG! Isn't that Bangtan Sonyeondan?!
Girl 2 : OMG ! YASSSS
(방탄소년단 ; Bangtan Sonyeondan)
Bangtan Sonyeondan / BTS is a noun.