Kiki

Noun
It is used to describe a person, especially a girl who always shows off/is flexing her belongings and she thinks she is better than everyone else. She's mostly rich and wears designer clothes, dreams of dating the quarterback and is unnecessarily rude. Aka, a total narcissistic spoiled brat. She has a superiority complex and is unnecessarily arrogant.

Think about the Mean Girls, or OMG Girls from the Kissing booth, Tess in Camp Rock or even Julliard from Work It. You get the idea.

"Look at Karen, flexing her Balenciaga jacket in front of everyone... such a Kiki."
"You're such a Kiki. You know that strutting around in those high heels is not gonna make anyone else feel bad about themselves."
"She got a nose job just cause she wanted to be prom queen so bad. What a Kiki."
"Kiki check! Her Dad bought her a Mercedes for her 16th birthday and now she's crying cause that's not the color she wanted."