Definition

When something or someone occupies your thoughts constantly without paying for the privilege. That song stuck in your head? Living rent free. Your ex? Rent free. That embarrassing thing you did in 2014? Penthouse suite, rent free, no plans to move out.

Example Usage

"The way my coworker pronounces 'espresso' as 'expresso' lives rent free in my head. It's been four years. I can't evict it."