The idea that someone should always be happy and carefree
He wanted her to always be sunshine and rainbows, even though in reality that does not exist for anyone.
Where there are tons of little, or quite large, bruises on your legs, arms, various parts of the body in different colors, causes may include abuse, weakness, etc.
Girl: "Oh my glob, there is a deadly rainbow on my leg!"
When you do everything sexual (for example: got sucked off, etc) but you didn't actually had any sex.
Kyle: So yesterday Kara sucked me off. It was totally great.
Chad: Dude you and Kara have been together for more than a year and still haven't had sex.
Kyle: Yeah I know, I'm totally getting blue balled.
Chad: It's called a virgin rainbow dude.
When you want to bang a person of every race
One of my life goals is to bang the rainbow
Someone who loves to do gay ships with anime, cartoon, or tv characters, or even real people.
Is a term that sounds hyper-sexual but really means to eat all sorts of colorful vegetables.
This chick had me over last night and really had me eat the rainbow. I never had so many vegetables.
When two or more companions lie on their back and puke in each others mouth.
"Me and Jerry did a Dirty Rainbow with my dad"