This term is commonly used to adress a very ugly person, and not only ugly but fake and stupid too. A karlyn, thinks that it is beautiful, but in truth, is quite the opposite. Also, karlyns are very dumb and think that a 51 is a perfect grade.
"'Damn girl, you have one big booty
'Thanks, I like it too.' - A Karlyn
'No girl, I mean you have a really huge booty
, have you considered dieting?'"
"WHAT A SLUT, she's such a karlyn."