a punch to the body in boxing, MMA and various other combat sports that combines a hook with an uppercut, resulting in the punch being delivered with a diagonal motion and the arm bent.
A flawless sex position which involes the male putting wrestling underhooks onto his female partner, and then proceeds to thrust while pulling down with his arms,resulting in what women like to call heaven. The double action of arms and hips create the perfect combination. Although slightly rough it always results in an A+ grade for performance. (Can be preformed in muiltiple positions, standing, sitting, missionary, etc)
During missionary sex, when the women begins to move around too much, you place your arms underneath hers in a double underhook fashion to prevent her from sliding any further.
Dude, Mike was fuckin'this bitch and he was pokin' her so hard he had to double underhook her so she wouldnt move around so much.
In missionary position, you wrap your right arm under her left leg and left arm under her right leg pulling both legs back and repeatedly pile drive your penis in her vagina with your ball slapping against her ass.