FREEBASE
Etymology
Noun
freebase (countable and uncountable, plural freebases)
(chemistry) The purified, dry form of an amine, especially an alkaloid natural product, that is normally used in solution.
(specifically) The purified, dry form of certain illegal drugs, especially cocaine.
Verb
freebase (third-person singular simple present freebases, present participle freebasing, simple past and past participle freebased)
To purify a drug by crystallization.
To use a purified drug, especially cocaine, by heating it and inhaling the fumes produced.
Source: Wiktionary