The stylistic and wealthy art of giving your partner three Dutch ovens, followed immediately by taking a Cleveland steamer in your partner's eyes, and squishing the shit back and forth, up and down between his/her eyelids.
Not to be confused with the Japanese term "Dekimashita", which means "Finished". "Deckermushita" is pronounced Deh-ker-mush-tuh.
Bro 1: Dude, I gave your mom fourteen deckermushitas last wednesday.
Bro 2: FUCK, HOW DO YOU HAVE THAT MUCH SHIT?