The act of wearing internally a butt plug during the day, all day.
Ie that dude from the climbing gym didn’t pick his bike up on the secret trailhead entrance and brought a friend, he is such a day plugger.
The large, hard, round mass that ends up in your rectum after you don't move your bowels for three days.
Man, I was just soaked in sweat after having to get that three day plugger out!