Cb, short for citizens band is a two way radio device for short distance communication. With no license required the CB's maximum output allowed by law is 5 watts, making for about 5 miles maximum communication with topograpical limitations considered.
With it's haydays in the 70's long gone by, the public has generally opted for the more modern cell phone to communicate.
At one time almost every other vehicle could be found with a CB.
Now more of a hobby,there are still a number of active enthusiasts.
Breaker, breaker 19 we've got a bear in the bushes at mile marker 18. Come back.
by Jag III November 14, 2004
Citizen's Band radio service:

radio frequency range, worldwide service:
26.965 to 27.405 MHz

still used all across the USA by truckers for the avoidance of police officers cops and in the rest of the world by terrorists and FARC

Channel 9- international emergency channel

Channel 19-international calling/trucker channel
"Breaker Breaker one-niner, this is Wohn Jayne, we got smokey on your tail and a beaver in a flop top at your 1 o'clock"
by IrishRepublicanArmy October 28, 2003
Citizen's Band radio. Public radio service in the 11 meter shortwave band. In North America, the frequencies are 40 channels from 26.965 kHz to 27.405 kHz in 10 kHz steps. AM (amplitude modulation) or SSB (single sideband) modes may be used. A CBer may not use more than 5 watts on AM or 12 watts PEP on SSB, yet the power restrictions are often flouted.

The FCC (US radio regulatory agency) once required licenses for CB. The popularity of CB in the 70s resulted in much illegal operation. The FCC dropped licensing requirements in the early 1980's.

North American CB today is a wasteland of cursing, vulgarity, sexual innuendo, jamming, music broadcasting, and heavily distorted audio due to improper radio modifications. Amateur radio (ham radio) operators have a particular dislike for CBers and CB lingo. CBers sometimes transmit illegally on ham radio frequencies and are often caught by vigilante hams with radio direction finding equipment. Ex-CBers who get ham licenses are often ostracized for using CB lingo on the air. It is a grave insult to call an American ham operator a CBer.
Heard on CB radio channel 14: (shouting, incomprehensibly distorted audio) "Roger roger breaker breaker 14 hear my radidio come on come on"

Ham 1: "Did you hear that new ham on the repeater? He was using CB lingo like 'what's your 20?'"

Ham 2: "Yeah, I'll have to pull him aside at the next hamfest and talk to him about it."
by poorbrokegradstudent August 23, 2010
He was preventing him from getting a booty call, therefore he was broadcasting casting from CB radio.
by Mattslash October 25, 2010
n. A metaphorical device in which a cockblocker uses to call another person on to accidentally or intentionally prevent a hook up.
(Tony is laying down the mac on a lady.)

Tony: So, I was descending Everest when I saw found an antique camera burried in the snow. It was pretty rad.
Tanya: Really? That's awesome. Was there film in it?
Tony: Yeah, I developed it the other...
(Jay interupts)
Jay: Dude, I'm so wasted! LOL
Jay: Yo, isn't that that one chick you boned last week?
Jay: *burp*
Tanya: *sigh*
(Tanya leaves abruptly)
Tony: Bro, why you gotta call me on the cb radio?
Jay: What?
by def August 9, 2006
What lamers played with before the internet was widely available
Breaker breaker, here's the rubber duck, you got your ears on c'mon? Kshhhht.
by jt July 14, 2003
The incoherent language spoken by African Americans on the CB radio that can be understood only by another fellow African American CB radio user.
sounding to a White person, "Bla Wa Na Wab Bla Bla Wa Na Bleb Dab Wab Dod Nob Bla Bla Bla Da Mutta Fuckka Dare Brake Brake"
by Maxwell June 27, 2004