1 definition by fratdaddy24601
a girls reward for an excellent night in bed. The shirt is one of the lucky male's T-shirts that serves as a trophy or badge left from the hookup
Do you think he'd give me his fav Vinyard Vines Tee for my formal shack shirt?
Kelsey: So cute! where'd you get that?
Amy: its just an old shack shirt
Kelsey: So cute! where'd you get that?
Amy: its just an old shack shirt
by fratdaddy24601 December 11, 2013