an officer of the rank held by young men immediately upon graduating from the government naval schools.
(initial capital letter) the title and rank of such a graduate.
(formerly) one of a class of boys or young men who formed the group from which officers were chosen.
3.
Also called singingfish. any toadfish of the genus Porichthys, having many small luminous organs on the underside and producing a buzzing sound with its air bladder.