(1):

(n.) In the United States navy, the lowest grade of officers in line of promotion, being graduates of the Naval Academy awaiting promotion to the rank of ensign.

(2):

(n.) An American marine fish of the genus Porichthys, allied to the toadfish.

(3):

(n.) Formerly, a kind of naval cadet, in a ship of war, whose business was to carry orders, messages, reports, etc., between the officers of the quarter-deck and those of the forecastle, and render other services as required.

(4):

(n.) In the English naval service, the second rank attained by a combatant officer after a term of service as naval cadet. Having served three and a half years in this rank, and passed an examination, he is eligible to promotion to the rank of lieutenant.