trocar /trō″kär/ [Fr, trois, three, carres, sides] , a sharp, pointed rod that fits inside a tube. It is used to pierce the skin and the wall of a cavity or canal in the body to aspirate fluids, to instill a medication or solution, or to guide the placement of a soft catheter. The trocar is usually removed, and the catheter, tube, or instrument is left in place. See also cannula.
