In ships of war, a kind of naval cadet, whose business is to second or transmit the orders of the superior officers and assist in the necessary business of the vessel, but understood to be in training for a commission. A passed midshipman is one who has passed an examination and is a candidate for promotion to the rank of lieutenant. See U. S. v. Cook, 128 U. S. 254, 9 Sup. Ct. 108, 32 L. Ed. 464.