v. Slang, -lined, -lin·ing, -lines. v.tr.
To inject (a drug, such as heroin) directly into a major vein.
v.intr.
To inject a drug intravenously.
adj.
Being in a principal or well-established position: the mainline churches.
mainliner main'lin'er n.
The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.
