Beat-Down is when a masculine alpha male is fucking a gay bottom or female, and while he's fucking them he puts his foot down on their back, and holds it there while he's roughly fucking them, beating the ass or pussy down.
v. (1) to verbally berate into submission (publicly) (2) to physically rough up or convincingly administer authority over another person or thing (3) the exercise of legitimate authority, rules, or known customs which leaves a person or persons in a poor position and often disappointed.
n. the act of beating down (2) a disappointing and unexpected result to an attempted action
Verb: Mr. Smith beat down that dude who came up on his porch asking for money.
Noun: (1) I had to throw a beat down on that punk ass. (2) That was a beat down.
To receive a BEAT DOWN would be equivalent to getting your ass seriously beaten by another person or persons; to have one's ass handed to them; to be "pounded into the ground" by someone who doesn't like you.