Of the remaining mainliners, the Christian Church (Disciples of Christ) has suffered most. It has lost 40 percent of its members and now claims only 1,146,000 faithful. Kenneth L. Woodward, Newsweek, 22 Dec. 1986
2
informal: a person who injects a drug into a vein : a person who mainlines a drug
She holds nothing back about the awful things done to her, or about her attraction to the social danger zones inhabited by strippers, heroin mainliners, rhino poachers, and guerrillas. Gilbert Taylor, Booklist, 1 Dec. 2000