midshipman(n = noun.person) - a temporary rank held by young naval officers in training;
is a kind of cadet, plebe

1.  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. [1913 Webster]

2.  An American marine fish of the genus Porichthys, allied to the toadfish; also called singingfish. [1913 Webster]

midshipman, n. (pl. -men)
1 Brit. a naval officer of rank between naval cadet and sub-lieutenant.
2 US a naval cadet.

N  sailor, mariner, navigator, seaman, seafarer, seafaring man, dock walloper, tar, jack tar, salt, able seaman, A, B, man-of-war's man, bluejacket, galiongee, galionji, marine, jolly, midshipman, middy, skipper, shipman, boatman, ferryman, waterman, lighterman, bargeman, longshoreman, bargee, gondolier, oar, oarsman, rower, boatswain, cockswain, coxswain, steersman, pilot, crew, aerial navigator, aeronaut, balloonist, Icarus, aeroplanist, airman, aviator, birdman, man-bird, wizard of the air, aviatrix, flier, pilot, test pilot, glider pilot, bush pilot, navigator, flight attendant, steward, stewardess, crew, astronaut, cosmonaut, parachutist, paratrooper.