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8.
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
64 160
 
9.
A term used for police. Usually when the person is doing something wrong or illegal.

police pigs
Shit! Run! The Five-O are coming! Hide the drugs!
by Ziggy Bop March 07, 2008
146 248
 
10.
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."
78 181
 
11.
a dance that involves five people
Shit son that was a great five-o!
by ballas4life February 16, 2009
27 161
 
12.
An object that is reminiscent of the 1950's.
That Lamp is so Five-O.
by YouDoanome November 12, 2006
18 153
 
13.
Meaning Police
Originated from New York
Mr Cahill, you like a God to me.
Like a god. Son I am God. God, Allah, Buddha all rolled up into one big Nigga.

Five-O.
Motherfucker got more shit on me, put me away for 20 or 30 years. That's why I gotta pay them so much money.
by Bally June 23, 2006
31 166
 
14.
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.
"o shit son, its the five o"
by gchild July 12, 2005
127 263