penguin

1. (obsolete or historical) An auk (sometimes especially a great auk), a bird of the Northern Hemisphere.Examples: "This last species of penguin, or auk, seems to be the same with the alca cirrhata of Dr. Pallis, Spicileg. Zool. Fasc. v. p. 7. tab. i. & v. fig. 1–3. F."; "More than a hundred years ago, for example, was seen the last of the great wingless penguins or auks, which early writers quaintly called " wobble-birds.""historicalobsolete

2. (slang) A nun.Examples: "Jake (John Belushi): What are we doing here? Elwood (Dan Aykroyd): You promised you'd visit the penguin the day you got out. Jake: Yeah. So, I lied to her. Elwood:You can't lie to a nun. We gotta go in and visit the penguin."slang

3. (juggling) A type of catch where the palm of the hand is facing towards the leg with the arm stretched downward, resembling the flipper of a penguin.

4. (UK, military, slang) A member of the air force who does not fly aircraft.Examples: "Although it is a permanent R.A.F. station (pre-war, that is), we meander about, even in the Mess, in battle dress and flying boots, sweaters, etc., much to the disgust of some of the more dignified 'penguins' […]"; "Notwithstanding his elevated status as the wing’s Senior Intelligence Officer, Monty, too, was a “penguin,” equal in that respect to an armament assistant, airframe mechanic, pigeon loftsman or any of the seventy-odd ground trades listed by the Royal Canadian Air Force at the war’s end."; "She may have been a “penguin”—an Air Force service member who didn't fly—but it sure beat being at home, as Brady had pointed out."UKslang