Green’s Dictionary of Slang

1. (also gumfoot) to investigate, esp. used of police officers or private detectives; thus gumshoeing as n.

1908		B. Fisher A. Mutt in Blackbeard Compilation (1977) 135: It is true I had Rudolph Tobasco gumshoeing for my lost quadruped.
1911		S. Ford Torchy 12: This duck from the post-office buildin’ showed up. He comes gumshoein’ around one noon hour [...] and he asks a whole lot of questions.
1922		Washington Times (DC) 12 Nov. n.p.: I let him get away with it until I can gumshoe around a bit.
1925		D. Hammett ‘Dead Yellow Women’ Story Omnibus (1966) 154: I had once, half-joking, promised to give the lad a fling at gum-shoeing.
1933		R. Chandler ‘Blackmailers Don’t Shoot’ in Red Wind (1946) 119: It was his night off and he was a great guy to gumshoe around on his night off.
1949		Monteleone Criminal Sl. (rev. edn) 108: gumfoot [...] to spy for the police.
1955		B. Schulberg On the Waterfront (1964) 116: How do you like them two gumshoein’ around, takin’ me for a pigeon.
1962		Ragen & Finston World’s Toughest Prison 802: gumshoe – To spy on or to observe.
1977		‘John le Carré’ Honourable Schoolboy 77: Gum-shoeing after Commercial Boris.
2002		B. Pratt Idea of Forever 53: I’m going to send Pablo out immediately to start gumshoeing and he’ll probably begin night here.

2. to walk softly, to creep around; thus gumshoeing as n. and adj.

1902		‘Hugh McHugh’ It’s Up to You 15: I left Tacks on guard and gumshoes away like Raffles, the busy burglar.
1912		G.R. Chester Five Thousand an Hour Ch. xxiii: Has that grasping old monopolist gumshoed into town again?
1922		Colton & Randolph Rain II 101: He wasn’t looking any too well when I saw him gumshoeing down the road this morning.
1937		P. Cheyney Dames Don’t Care (1960) 122: I leave him, open the door an’ start gumshoein’ up the stone steps.
1943		R.L. Bellem ‘Shakedown Sham’ Dan Turner – Hollywood Detective May 🌐 I gumshoed over to the connecting door between my quarters and the adjoining 607. I put my ear to the panel; listened.
1949		J.H. Burns Lucifer with a Book 43: He is the camouflaged forceps of Mr. Pilkey’s Puritanism, of his gumshoeing cynosure.
1954		A. Petry Narrows 247: She and Link walk gumshoe when dey come in [...] Dey gumshoe in, through door.
1998		W.J. Schafer Mapping the Godzone 156: Ever since he got dubbed ‘the Spook’ at school he’s never happy unless he’s gumshoeing around in the dark.

3. to walk, to stroll.

1915		S. Ford Shorty McCabe on the Job 139: Is it the style where you come from [...] to gumshoe around and peek in the windows to see old friends?
1942		R.L. Bellem ‘Daughter of Murder’ Dan Turner – Hollywood Detective Dec. 🌐 On the third floor corridor I gumshoed toward my portal.
1955		B. Appel Tough Guy [ebook] [A] federal who’d gumshoed the backroads upstate and uncovered the new route being used by Big Bill Dwyer’s gang.
2004		Nystrom & Konn Lonely Planet Bolivia 56: You’ll get plenty of exercise gumshoeing up and down the Prado.

4. to be quiet.

1913

‘Lord Ballyrot in Slangland’ in Tacoma Times (WA) 23 July 4/4: Nix on the patriotic and ragtime selections every time you did a shovel full of canned broth into your map. Gum-shoe, kid, gum-shoe.

5. (US teen) to search out amorous couples in parked cars in order to surprise them by shining a light on them.

1949–51

in M. Daly Profile of Youth 233: Even when fellows are out stag, a car is indispensable to ‘gumshoeing,’ the practice of driving to a favorite necking spot and beaming a flash or spotlight into parked cars.