free·base or free-base 
(frēbās′)
(frēbās′)v. free·based, free·bas·ing, free·bas·es or free-based or free-bas·ing or free-bas·es
v.tr.
1. To purify (cocaine) by treating its powdered hydrochloride form with an alkaloid solution such as ammonia and then using a heated solvent to separate out the precipitate.
2. To use (cocaine purified in this way) by smoking it or by inhaling the fumes after burning it.
v.intr.
To prepare or use cocaine purified in this way.
n.
Cocaine purified by this method.
freebas′er n.