A term used for police. Usually when the person is doing something wrong or illegal.

police pigs
by Ziggy Bop March 8, 2008
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Shit five-o finna show up and shut our car meet down.

Run fast motherfucker it's the five-o

Someone phoned/called the five-o on us.
by Agerix December 30, 2016
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ACTUALLY....five o comes from the 80's US patrol cars mustang 5.0 litre engine. It called to alert to an oncoming cop car.
by gchild July 12, 2005
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n. When someone says five o they are referring to police. This was derived from the engine of the ford cop cars. The cars ran on 5 liter engines and had a 5.0 symbol on the side. In fact, the same symbol is used on the sides of the 5 liter ford mustangs.
Oh shit, five o. Dipset; we'll meet by the car in 10.
by LGND May 15, 2014
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Pigs -- sometimes hair-trigger killers with screamin' amps, party lights and big guns (the bad kind of each) anywhere, but specifically on any of the Hawaiian Islands.

Generally: anyone, anywhere packin' a badge or talkin' to someone who does; Cops; LVPD on bicycles; LAPD; NYPD; Sheriff's Deputy; CHiPs; Highway Patrol; State Police; Texas Ranger; feds; U.S. Marshall; DEA; BATF; undercover detective; the man; gubbamint agent; revenuer; Dog the Bounty Hunter; Officer of the Court; DA, judge; meter maid; security guard; narc; snitch; CI.

Even more broadly: paranoid label for anyone out-of-place in the hood; a person (potential witness) suspected of surveillance; someone who trades their legal troubles for incriminating testimony against someone else.
"This is McGarrett, FIVE-O. You're dusted (busted).
Book'em Dan-O (or Book him, Danno)."

"The Feds are bastards. Even Captain Steve McGarrett of Five-O don't like 'em for their inept and abusive heavy-handed tactics."
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Route 50, on the Eastern Shore of Maryland has been renamed to "The Five-O" for it's ease of rolling off the tongue and it's "hoodness" factor.
We pulled up in our sled to the DQ just off of the five-o and got a Blizzard.
by briantbilane December 19, 2009
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although it does come from hawaii 5-0, my undestanding is that it specified undercover officers, or detectives
Yo, you think he's five-o? wait til he leaves before you light that shit.
by swervon 617 October 25, 2007
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