Definitions by S.O.M.I.

Kiersten 

A sweet girl, generally pretty with light brown hair. A Kiersten is usually dissatisfied with her looks, and is constantly changing things about herself to feel less insecure. Expansive chest, green-blue eyes, petiteness, and smarts are common in a Kiersten. Possibly awkward.

Guy 1: "Didn't that girl have a different hair colour yesterday?"
Guy 2: "Yeah. She is such a Kiersten."

--
Guy: "Why does our teacher even ask US the questions?"
Girl: "I know, right? If she wants to know the answers so bad, all she needs to do is ask Kiersten."

Kiersten by S.O.M.I. January 3, 2011