big dog, n. — Green’s Dictionary of Slang

big dog n.

1. (US) an important person; also attrib.; thus Big Dog Upstairs, God.

1833		J.S. Jones Green Mountain Boy I iii: For the rale genuine grammar larnin’, I am a six-horse team and a big dog under the wagon [DA].
1847		J.M. Field Drama in Pokerville 35: He [...] was ‘a perfect gentleman when he was sober,’ and, altogether, the ‘big dog’ at Pokerville.
1882		A. Pinkerton Mollie Maguires and the Detectives 24: ‘Yes,’ said Dormer, ‘Lawler is the big dog in these parts now; besides he kapes a good tavern, and will see no old-timer, or young one either, for that matther, sufferin’ from want while he can relieve him!’ [F&H].
1900		Bulletin (Sydney) 24 Feb. 13/2: There are places in Sydney where you can get a decent meal with wine for 9d. nowadays, and in accordance with this almighty tendency the big dogs of the bar are glad to reach out and seize even such small things as District Court Judgeships.
1904		Sun. Times (Perth) 26 June 4/8: They call this push the ‘cornfeds,’ and they bulge like brewery vats / And they’re big dogs with the donahs.
1940		B. Appel People Talk 281: He thought he’d be the big dog.
1947		B. Stiles Serenade to the Big Bird 14: Before missions we used to eat at the big dog’s mess-hall, Number 1, with the colonels and the majors.
1955		R. Graziano Somebody Up There Likes Me (1956) 207: He got such a boot out of being a big-dog fight manager.
1965		T. Burns Haber ‘Canine Terms Applied to Human Beings’ in AS XL:2 93: big dog. An individual of great importance.
1977		(con. 1960s) D. Goines Black Gangster (1991) 40: I’ll be the big dog down there.
1992		J. Mowry Way Past Cool 225: He too puss to go messin with the big dogs, so he schemin on us.
2001		J. Stahl Plainclothes Naked (2002) 94: Does being a priest make you closer to the Big Dog Upstairs?
2001		Source Aug. 48: Are they really an inspiration to the big dog or just hangers-on?
2001		(con. 1990s) in J. Miller One of the Guys 81: ‘Don’t nobody wanna fuck with him. That’s the big dog. Can’t hang with the big dog , you better stay your ass on the porch with the poodles’.
2006		Ace & Invisible 1Xtra 13 Apr. [BBC radio] He’s running with all the big dogs.
2015		J. Spades ‘What’s Going On’ 🎵 You know they call me big dog when they see me on the roads / [...] / And the fans always screaming when they see me at a show.

2. a thug; a bouncer n.¹ (10)

1884

Good Words June n.p.: He was ‘big-dog’ to a disorderly house.

3. (US) a greyhound bus.

1975

L. Dills CB Slanguage 11: Big Dog: Greyhound bus.

4. as a term of address.

2001		G. Pelecanos Right As Rain 190: Don’t worry, big dawg, I’m gonna send Adonis and his shadow.
2023		Rayman & Blau Riker’s 398: I don’t know where I’d be without you, big dog.

In phrases

like a big dog (adv.) (also like a moose)

(US campus) having qualities to do with achievement, success, intensity.

1983		Eble Campus Sl. Nov. 1: get off like a big dog, throw down like a big dog, pee like a big dog.
1985		Eble Campus Sl. Oct. 7: like a moose – in a big way.
1986		Eble Campus Sl. Nov. 6: like a big dog – with intensity.
1996		Eble Sl. and Sociability 70: To act like a big dog is to do something ‘with intensity’ (‘I was running like a big dog to catch my bus’).

run with the big dogs (v.)

(US campus) to do anything anyone else can.

1981		Eble Campus Sl. Fall 6: run with the big dogs – [...] He couldn’t eat as many slices of pizza as I could – he shouldn’t run with the big dogs. If you can’t run with the big dogs, get out of the pack.
1983		Eble Campus Sl. Nov.
1996		Eble Sl. and Sociability 70: To run with the big dogs is ‘to do anything that anyone else can, rise to a challenge’ (‘I think I can run with the big dogs in honors English’).