Green’s Dictionary of Slang

run-out powder n.

[a fig. SE powder that inspires speed; note powder v.1 ]

In phrases

give (someone) a run-out powder (v.) (also ...a walk-out powder)

(US) to dismiss, to send packing.

[US]O.O. McIntyre New York Day By Day 16 Sept. [synd. col.] The crowd gave him a ‘run out’ powder.
[US]O.O. McIntyre New York Day by Day 15 Aug. [synd. col.] The park officers usually give the sleepers [i.e. in Central Park] a ‘walk-out powder’.
take a run-out powder (v.) (also take a run-out)

to escape, to run away.

[US]T.A. Dorgan in Zwilling TAD Lex. (1993) 71: He mooched a railroad ticket East, fled with the rest of the gents who took the run-out powders then and landed in Baltimore without enough coin to buy a pack of Durham.
[US]T.A. Dorgan in Zwilling TAD Lex. (1993) 71: I wouldn’t mind her taking a run out if I hadn’t been so good to her.
[US]Wash. Times (DC) 14 Feb. 20/1: Some Janes Take a Runout Powder on the Judge.
[US]P. & T. Casey Gay-cat 197: Aw, say now, ma’m; I wouldn’t take no run-out powders on yer that way.
[US]D. Hammett ‘Fly Paper’ Story Omnibus (1966) 56: You knew Sue was planning to take a run-out on you with Joe?
[US](con. 1920s) J.T. Farrell Judgement Day in Studs Lonigan (1936) 540: Pete Webb just took a run-out powder on his wife.
[UK]P. Cheyney Don’t Get Me Wrong (1956) 59: Whatever it was made him take a run-out before finishin’ off the letter to Scattle happened in Mexico City.
[US]W. Winchell ‘On Broadway’ 30 Oct. [synd. col.] Lots of the Honorables were fixing to take a run-out. They weren’t hiding the reason for their scream either.
[US]B. Schulberg Harder They Fall (1971) 294: If he took a run-out powder now, Toro would end up in the river.
[UK]I, Mobster 119: You saying I should take a run-out powder?
[US]W.R. Burnett Little Men, Big World 93: Maybe there was going to be trouble; maybe Leon was certain of it and had taken a runout and was sweet-talking both sides.
[US]A. Zugsmith Beat Generation 11: He wanted to get help for her before he took his runout.
[UK]C. Stead Cotters’ England (1980) 214: It’s a bloody runout powder you’re taking. You know you could work here at home.
[US](con. 1940s–60s) Décharné Straight from the Fridge Dad.