A Holiday celebrated on January 23rd, in which people only eat Grilled cheese and orange juice for every meal that day due to lack of money from holidays or they just like Grilled Cheese and Orange juice.
This is when you go to a hotel with a coworker for sex during the work day. It is called this because, much like a grilled cheese sandwich it is fun, tasty, and kinda sticky, but ultimately unhealthy.
"I had a standing "grilled cheeselunch" with Tiffany in accounts every Friday, until she quit."
When your engine is shot because you have tried to cook grilled cheese in the furnace you use to boost your car in a post apocalyptic world. And then you pull it out and throw it in a lake because it fucked up your engine. From the movie Double Dragon starring Robert Patrick and Mark Dacascos.