free base

Noun

freebase (countable and uncountable, plural freebases)

1. The purified, dry form of an amine, especially an alkaloid natural product, that is normally used in solution.
   • 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
2. (specifically) The purified, dry form of certain illegal drugs, especially cocaine.
   • 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

See all 4 meanings of freebase