To be gay or to have gay qualities or traits.
"man.. i think Adam's got rainbow syndrome. i saw him at a gay bar makin' out with a guy last night"
by victr0la January 23, 2007
Extreme urge to go out caused by refusal to do so with your friends the night before. Often leads to drinking at inappropriate hours and attempting to convince everyone around to come out.
Why is Charlie drunk in the morning?- He has got the rainbow syndrome, did not go clubbing with us last night.
by kultuhtu December 14, 2017