1 definition by cain614
A practice where a bisexual wears a green shirt with collar. The collar is worn up, indicating a desire to have sex with anyone. The offer is accepted by the person turning the wearers collar down.
"Why's that girl wearing the green shirt with the collar up?"
"She's greenlighting fool... turn her collar down and get some!"
"She's greenlighting fool... turn her collar down and get some!"
by cain614 July 6, 2005