K3U 

1. K3U is short hand for I <3 U.
2. I <3 U = I love you, basically.
3. K3U originated from Central California in Late 2002.

Girl geek: "I love you, babe!"
Guy geek: "K3U too hun!"

K3U by M. Lohse July 11, 2006

K3U 

I Love You => I <3 U => K3U

therefore, the I and the < combine to be a K then come the 3 and the U which become K3U

50: K3U Lloyd.
Lloyd: K3U too fiddy.

K3U by J2TEH OOLIA July 11, 2006