A euphemism for throwing up.
Dude, this kid in my class got sick and totally rainbow smiled alllll over the room. He couldn't even make it to the bathroom!
dari El Chin Chon Jum'at, 06 Februari 2009
1 more definition
to smile out of happiness while crying of sadness
she had lost all hope, but love in friendship made her dawn a rainbow smile
dari audiodecoy Senin, 04 April 2005