Green’s Dictionary of Slang

1. (orig. UK Und.) a holding cell, e.g. in a police station or courtroom, surrounded by steel mesh or an open ‘cage’ made of steel bars (orig. of wooden bars).

1809		Horry & Weems Life of General F. Marion (1816) 232: The tories were all hand-cuffed two and two, and confined together under a centinel, in what was called a bull pen, made of pine trees, cut down so judgematically, as to form by their fall, a pen or enclosure.
1843		Times & Seasons 1 July 253/4: All the witnesses, forty at a time, have been taken by force of arms, and thrust into the ‘bullpen’ in order to prevent them from giving their testimony [DA].
1879		A. Pinkerton Reminiscences 213: His companions [...] had been herded in the ‘bull-pen’.
1883		Sweet & Knox On a Mexican Mustang, Through Texas 595: We may be caught by the provost-guard, and put in the bull-pen.
1898		F.P. Dunne Mr Dooley in Peace and War 11: ‘Look here,’ says he, [...] ‘if ye don’t lave me counthryman out iv th’ bull-pen in fifteen minyits be th’ watch,’ he says, ‘I’ll take ye be th’ hair iv th’ head an’ ...’.
1909		‘O. Henry’ Roads of Destiny 162: Unlock him at seven in the morning, and let him come to the bull-pen.
1915		G. Bronson-Howard God’s Man 147: The prisoners pushed into the ‘bull-pen’ – a huge square room, a stone floor filthy with tobacco juice, no seats, one side open to the gaze of privileged persons – reporters, [...] shyster lawyers.
1922		Cleveland Foundation Survey of Criminal Justice in Cleveland 1 60: It is no longer necessary for police court runners to look over the contents of the ‘bull pen’ for old and new clients.
1926		J. Black You Can’t Win 72: I was taken downstairs and locked in a cell; I saw no more of the ‘bull pen’ where I spent the night.
1932		R.E. Burns (con. 1929) I Am a Fugitive 158: The steel-barred door of the bull pen was unlocked.
1942		W.R. Burnett Quick Brown Fox 244: In one police precinct the bull pen was the scene of a brawl which lasted half the night.
1952		‘Hal Ellson’ Golden Spike 240: They were sent to the bullpen to await the wagon.
1963		B. Hecht Gaily, Gaily 118: [They] would have been arrested on opening nights and their casts carted to the Harrison Street bull pen.
1973		D. Goines Street Players 122: There was a large bullpen right off the courtroom.
1992		S.L. Hills Tragic Magic 87: I’m sitting in the bull pen and I’m waiting.
1999		E. Bunker Mr Blue 283: The bailiffs closed in and took me to the bullpen beside the courtroom.
2023		Rayman & Blau Riker’s 8: I find myself in a bullpen [...] a small cell like fifteen by ten and there’s anywhere from like twenty to thirty men shoved in there.

2. (US) a small house or room used by a prostitute; thus a cheap brothel.

1867		Nat. Police Gaz. (NY) 12 Jan. 4: They keep a bad old ‘lush drum,’ and a couple of ‘bull pans.’ [sic] [HDAS].
1935		A.J. Pollock Und. Speaks n.p.: Bull pen, a cheap crib of prostitution surrounded by a fence.
1939		D. Maurer ‘Prostitutes and Criminal Argots’ in Lang. Und. (1981) 117/1: BULL PEN. A cheap house. Also cathouse, hook-shop, nanny-shop, nautch house.
1970		in P.R. Runkel Law Unto Themselves 259: My uncle took me to a bullpen [...] A whorehouse.

3. (US police) the holding cage in a precinct house.

1949		Monteleone Criminal Sl. (rev. edn).
1994		N. McCall Makes Me Wanna Holler (1995) 142: We were thrown into the bull pen, a huge holding cell, about forty feet square, filled with thirty or so drunks, junkies, and assorted other losers.

4. (US) any type of enclosed waiting area.

1903		in ‘O Henry’ Works 438: The bull-pen [...] the warden’s outer office.
1938		W. Smitter F.O.B. Detroit 9: There were thirty or forty fellows in the bull pen, sitting on benches.
1944		Chicago Daily News 10 Feb. 10/3: After waiting two hours in the ‘bull pen’ outside the employment office, I was finally escorted into the inner sanctum [DA].
1964		E. Wilson Earl Wilson’s N.Y. 377: They pour the hot sake, they bow, they smile, they cut their steaks – and in a ‘bull-pen,’ sit literally dozens of others waiting to be summoned.
1976		N. Thornburg Cutter and Bone (2001) 39: Bone saw one of the secretaries in the bullpen area nod to a young woman sitting next to her desk.

5. (US) a prison exercise yard or internal association area.

1912		D. Lowrie My Life in Prison 392: The cells are preferable to the ‘bull pen’ with its fetid miasma.
1935		N. Algren ‘Thundermug’ in Texas Stories (1995) 69: Somebody [...] shoved him out of the cell into the narrow bull pen.
1946		Mezzrow & Wolfe Really the Blues 48: We were let out of our cells to exercise in the bull pen.
1955		L. Allen Hot Stove League 107: Bullpen, of course, is also used in prison slang to designate the fenced-in area where prisoners are permitted to exercise.
1960		(con. 1950-1960) R.A. Freeman Dict. Inmate Sl. (Walla Walla, WA) 20: Bull-pen – an enclosed area where male prisoners are allowed to exercise and fraternize; cow-pen for women inmates.
1970		B. Seale Seize the Time 226: After I came back from court, they called me out of the bullpen.
1991		L. Bing Do or Die (1992) 8: You look to your right, into the big room that’s mostly an enclosed bullpen.
1997		Simon & Burns Corner (1998) 107: Gary gets the bad news when he’s pulled out of the bullpen in the afternoon.

6. (US prison) a punishment cell.

1928		J. Callahan Man’s Grim Justice 151: They stripped me naked when they got me to the bull pen.
1936		(ref. to 1920s) L. Duncan Over the Wall 86: In the bullpen, I really learned what the word ‘stagnation’ meant.
c.1943		‘Bill O. Lading’ You Chirped a Chinful!! n.p.: Bull Pen: Where a soldier can be alone with his thoughts.
1970		(con. 1910s) Gaddis & Long Panzram (2002) 63: The bullpen – a prison within a prison – was to be remembered as a symbol of John Minto’s administration.

7. (US) any enclosure (open-plan office, college dormitory, factory changing room, communal living quarters, etc) where a group of men and/or women work, associate, gossip etc.

1943		J.W. Work III Work Ms in Gordon & Nemerov Lost Delta Found (2005) 120: [T]he levee quarters were frequently tents—individual tents for a man and wife, large tents called ‘bull pens’ for groups of single men.
1950		Goldin et al. DAUL 36/1: Bull pen. 1. A dormitory or enclosure where men sleep en masse.
1967		R. Conot Rivers of Blood 125: In the southeast area office of the BPA the social workers are packed together in one huge bull pen, desk nudging desk, row upon row, typewriters clattering, telephones jangling, human voices intertwining like a mass of spaghetti .
1979		E. Torres After Hours 22: Ol’ Saso had hisself activity in the bullpen.
2004		J. Ellroy ‘Hot-Prowl Rape-O’ in Destination: Morgue! (2004) 265: The Narco bullpen: doom-deep in depression.
2012		(con. 1954) ‘Jack Tunney’ Tomato Can Comeback [ebook] Who should pay a call on me in the bullpen by Tom Garrick himself.
2023		J. Jackson Pineapple Street 256: She would have carried her cooler of breast milk past the bullpen of associates mooing like cows.