Most commonly Heard Word in Kpop

I was listening to B.A.P Coma and then I realized, the word that most stands out when I listen to Korean music is Opso...Wae?! Out of all the words, that word sticks out like a naked body in a fully clothed line of people. (Excuse reference, I dont know what made me think of that). Either way, what is the most common word or the word that most sticks out when you listen to kpop?

I jist felt like putting this great standstill of Jackson oppa. @poojas @aimeeH @vixenvivi @b1a4bts5ever @netchtibates @stephanieduong @szewwy @kpopandkimchi @b2utyrisa @sharayahtodd @sugajin94 @reddviolet @eringregory @emealia @katiems @baileykayleen @adorkabledolly @devonarce @solodaywithb1a4 @caitlind9898 @passthesuga @trollied @starbabes @yehet27 @laugh7love7live @kpopgaby @xinnim @robertakm64 @prettieeEmm @parkmeifan @marilovexoxo