To be so arrogant as to be extremely irritating to everyone and with no real repercussions, much like an itch between the shoulderblades that you just can't reach.
Ashley is insufferably Irrogant with judgemental eyes and her nose in the air, at a party she insisted loudly that phone cases are for poor people and then hilariously she dropped her phone in front of everyone, but it didn't even crack. What a smug, irrogant bitch!
Ulzzang true definition is "best & "face" = best face in korean. They are basically people with above average looks, sometimes with the use of photoshop and haduri who post their pics online, some becoming internet celebrities.
"Hey, see that chick over there? She's pretty enough to be an ulzzang. :D"