Mixing either heroin and cocaine or heroin and crack cocaine. Usually injected, but sometimes the cocaine is snorted and the heroin injected.
speedballing is bliss. a fucked up bliss.
by TFS January 6, 2006
The mixing of cocaine and heroin/morphine simultaneously. May also refer to mixing of stimualates such as amphetamines with other opiates or benzodiazapines. The mixing of stimulant and depressant is intended to "confuse" the heart and/or respiratory system.
Yo that stupid f*cker was speedballing all night. Dumb sonofabitch.
by RobKnowledge April 16, 2008
speedballing refers to mixing herion and cocaine. both substances can be mixed together and snorted. or injected if you're extremely dumb. apparently it gives the feeling of falling down an escalator. it confuses the heart, because herion is a "downer" and cocaine is an "upper." so herion slows the heart down while cocaine speeds it up. its an easy way to have a heart attack if you aren't careful. yet to be experinced haha.
last night, i decided to try speedballing dude. it was fuckin ridiculous; i didn't even know what was going on.
by OhhhhhxNOoooo10 May 23, 2009
Speedball- An IV injected mix of heroin & cocaine. This is one of THE most dangerous 2-drug combos known. Speedballing is most often done with the mixture of both drugs in one syringe that's injected. Speedballing not only has a high mortality/death rate, but loss of limb and other problems can arise.

Some inject each drug separately, often a syringe of heroin injected in one arm (or any where else they have a good vein- groin, leg, etc) immediately followed by an injection of cocaine. Sometimes people will shoot (inject) one of the drugs, while having someone else simultaneously shoot the other. Rarely, the Speedball mix is snorted instead of injected but the high is said to be less intense, as IV drugs are usually more potent than snorted drugs, but it's still highly dangerous.

Speedballs are said to cause 1 of the strongest highs... if you live through it. Mixing this upper (cocaine) and downer (heroin) is suppose to counteract some negative effects of the drugs, while also causing an extreme rush and a euphoric high with the "good" effects of both drugs, including the dangerous ones. Contrary to popular belief, Speed, Meth Amphetamines, and other drugs are not used in Speedballs. Historically many used morphine or other opiates instead of the heroin, but most people don't consider this a "true" Speedball now. Some mix benzodiazepines (Xanax, Valium, Klonopin, Ativan, etc) & amphetamines and call it a Speedball, but again this is not considered a true or real Speedball.
John Belushi, River Phoenix, Chris Farley, Jean-Michel Basquiat, MLB Player Ken Caminiti, Pete Farndon, Zac Foley, Chris Kelly from the group "Kris Kross", and Eric Show are just a few from the long list of celebrities who died from doing Speedballs.
by Dr. DontDoIt January 25, 2014
A mixture of heroin and cocaine administered intravenously. This combination offers the best of both drugs. The lady (coke) gives you a rush of intense euphoria followed by the soporific effects of your boy (heroin), thus effectively eliminating the anxiety and depression that follows when shooting up cocaine by itself.
Me: I've never smoked crack but I've done speedballs.

You: You're fucking kidding me, right? You've shot up coke and smack? I'm breaking up with you, Dumbass.
by kookaburra March 17, 2015
The combination of the narcotic heroin and stimulant cocaine mixed together and injected together in a single shot. When administered IV, the speedball produces the best rush/high in the world of drugs and is the most deadly of procedures as far as getting loaded. Highly addictive. Beyond destructive. Will bring any addict to their knees. It will call you and lure you, lie to you and kill you. Like alcohol and pills as well. This is the worst though. That is why it is the best.
"Man, my habit and tollerance were getting out of control. I was shooting about eight to ten speedballs a day just to stay high and not get sick."
by Martin Throttle June 29, 2006
Speedballer (noun) Most elite of paintball players, breed: different. Able to ruin a little kids paintball party in a matter of seconds. Can dominate the paintball field like a virgin in fortnite.
Carter: “Is that a real speedballer?”
Brandon: “Yeah, that’s Pierson alright. He definitely gets pussy!”
by Pube plucker December 21, 2020