In fightiing, playing, or BDSM sex play, to use your foot to push another person face first down into mud, muck or whatever. Of course, before you can bootplant, you have to get the other person in a face first lying or kneeling position.
AFter kicking him in the nuts, he fell to his knees. I kicked his back to make him fall forward and then did a bootplant on him in the cowshit.
by bubdub July 31, 2012