Direct Lift Control is a TriStar device used to keep the aircraft attitude constant on an auto ILS. Other aircraft may also use it.
Normally, if you want to increase your rate of descent, you push the stick forward, the elevators go down and the aircraft pitches down. With DLC small stick movements on the approach lead to the spoilers moving in or out to decrease or increase rate of descent keeping the attitude constant. Large stick movements change the attitude as well.