verb (used without object), mainlined, mainlining. Slang.
to inject a narcotic, especially heroin, directly into a vein.
to use or enjoy something without restriction: to mainline on TV movies.
verb (used with object), mainlined, mainlining. Slang.
to inject (a narcotic, especially heroin) directly into a vein.
to use, enjoy, or imbibe (something) without restriction: mainlining coffee all day long.
having a principal, established, or widely accepted position; major; mainstream: the membership of mainline churches.
Americanism; v., adj. use of main line