Green’s Dictionary of Slang

1. an identification parade.

1850		N.-Y. Daily Trib. 5 Jan. 1/7: SHOW UP. -- Joseph Lindsey, well known as an English Burglar and convict, was on Friday afternoon arrested and taken to the Police station, Second ward, for the purpose of making the policemen acquainted with him.
1861		(con. 1840s–50s) H. Mayhew London Labour and London Poor I 420/1: I was at work at the same time as he was, and I kept pilfering, and at last they bowled me out. (loud cheers). I got a showing up, and at last they turned me away.
1929		Hostetter & Beesley It’s a Racket! 238: show up—Parading of captured criminals or suspects at police headquarters, so they may be studied by detectives for identification or future recognition.
1931		Boston Globe (MS) 12 May 4/3: The men were paraded [...] at Detective Headquarters in a series of ‘show-ups’.
1937		(con. 1905–25) E.H. Sutherland Professional Thief (1956) 127: That decreases his chance of being identified in the showup for a heavy job (crime of violence).
1944		C.B. Davis Rebellion of Leo McGuire (1953) 216: When they put me on the showup they made me wear the sunglasses.
1949		N. Algren Man with the Golden Arm 186: Held Fri. 9 pm to Tuesday showup 96 hours.
1953		T. Runyon In For Life 54: With two other prisoners I was put in a ‘show-up’.
1968		J. Hersey Algiers Motel Incident 133: He was positive in the show-up there for Armed Robbery.
1980		(con. 1940s–60s) H. Huncke ‘Alvarez’ in Eve. Sun Turned Crimson (1980) in Huncke Reader (1998) 181: I was taken upstairs to the show-up and then down to a courtroom.
1990		(con. early 1950s) J. Ellroy L.A. Confidential 58: A show-up tomorrow, prisoners would be there to ID the roughnecks.
1991		(con. 1920s) O.D. Brooks Legs 113: If you don’t have a key, you better crap one or you’ll be in the show-up tomorrow.

2. attrib. use of sense 1.

1969		‘Iceberg Slim’ Pimp 167: You can jig a few steps on the ‘show up’ stage.
2000		J. Ellroy ‘Grave Doubt’ in Destination: Morgue! (2004) 88: The show-up room/Houston PD. Five black males [...] Gary Graham in slot 3.

3. (Aus.) a revelation.

1908

Sun. Times (Perth) 31 May 1/1: A couple of money-lenders are in for a sensational show-up [...] their Shylockian transactions call for the interference of the law.

4. an embarrassment.

2000

J.J. Connolly Layer Cake 121: This afternoon’s meeting was a fiasco, a real show-up.