Definition of "freebase"

The freebase is heated in a retort, foil, or other container and the vapor is inhaled as the freebase vaporizes.

1987, Richard Seymour, David Elvin Smith, The Physician's Guide to Psychoactive Drugs, page 75

On June 9, 1980, national attention was brought to cocaine freebasing when comedian Richard Pryor suffered third degree burns allegedly while using a butane torch to heat cocaine freebase he had prepared with ether.

2002, Edith Fairman Cooper, The Emergence of Crack Cocaine Abuse‎, page 18

Note: this freebase methedrine will actually be a mixture of the DL and L-forms, from which the L-form is the most common used in the preparation of methamphetamine.

2007, Jared Ledgard, A Laboratory History of Narcotics, Volume 1: Amphetamines and Derivatives, page 108

That day, I gave a class on making and using freebase. This was one thing that was to be done perfectly, or you could end up with glass and freebase all over you.

2011, Manuel Suarez, To Be Or Not to Be a Real Cop‎, page 72

Richard, one of my friends in L.A., claimed to have invented freebasing— smoking cocaine in its base form—though it's likely that what he meant was that he introduced a whole bunch of people to the process.

2009, Mackenzie Phillips, High On Arrival‎, page 82

With his nostrils ravaged, Crosby turned to drinking Cocaine mixed in glasses of wine, then took to smoking it by the novel technique of freebasing, where the drug is distilled down to its purest form through a process of filtration using ammonia and ether.

2010, George Case, Out of Our Heads: Rock 'n' Roll Before the Drugs Wore Off‎, page 169

Roger Ebert pretty much agrees with Siskel's dismissive attitude toward the film, saying he only watched it because it was about freebasing cocaine and he wanted to see that, since he had heard so much about it.

2013, John Markert, Hooked in Film: Substance Abuse on the Big Screen‎, page 159