Liposuction: The surgical suctioning of fat deposits from specific parts of the body, the most common being the abdomen, buttocks, hips, thighs and knees, chin, upper arms, back, and calves. A hollow instrument called a cannula is inserted under the skin to break up the fat. A high-pressure vacuum is then applied to the cannula to suck out the fat. Liposuction is one of the most common cosmetic operations in the US. See also liposuction, tumescent; liposuction, ultrasonic-assisted.