What is to reduce (an equation) in a lower degree. To depress the pole (Naut.), to cause the sidereal pole to appear lower or nearer the horizon, as by sailing toward the equator called?

depress — (Math.) To reduce (an equation) in a lower degree. To depress the pole (Naut.), to cause the sidereal pole to appear lower or nearer the horizon, as by sailing toward the equator. (Webster's 1913.)