Someone who abuses or is addicted to an amphetamine, especially methamphetamine. (Also written as "speed head.") This state is a thoroughfare for methamphetamine to the rest of the country, so it's little wonder that there are so many speedheads here.
speed freakand speedhead
n. a drug user who injects methamphetamine; an amphetamine user. (Drugs and general slang.) Speed freaks, not heroin addicts, account for a high proportion of drug-related crime.
See speed freak