To make a cut in a boil or abscess to remove the pus.
To pierce, open, or cut into, as a boil for drainage.
To pierce or cut an abscess or boil in order to release accumulated pus. Abscesses and boils (called furuncles) should never be lanced by a person at home; this can result in the spread of infection, which is usually caused by bacteria. Doctors lance lesions in sterile surroundings, inserting a drain if the infection is large or deep.