The Collaborative International Dictionary of English v.0.48:
free-base \free-base\, Free base \Free" base`\(fr[=e]" b[=a]s`), v. i. To ingest the basic form of a narcotic drug, usually by injection. [PJC]WordNet (r) 3.0 (2006):
free-base v 1: use (purified cocaine) by burning it and inhaling the fumes [syn: free-base, base]