main line(redirected from mainlining)
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A group of suburbs of southeast Pennsylvania. The fashionable area was named after the chief railroad line traveling west from Philadelphia.
1. A principal section of a railroad line.
2. Slang A principal and easily accessible vein, usually in the arm or leg, into which a drug can be injected.
1. (Railways) railways
a. the trunk route between two points, usually fed by branch lines
b. (as modifier): a main-line station.
2. (Automotive Engineering) US a main road
(Recreational Drugs) (intr) slang to inject a drug into a vein
having an important position, esp having responsibility for the main areas of activity
1. a principal highway or railway line.
2. Slang. an accessible vein that can be used to inject a narcotic.
v. -lined, -lin•ing,
1. Slang. to inject a narcotic directly into a vein.v.t.
2. Slang. to inject (a narcotic) directly into a vein.adj.
3. having a principal, established, or widely accepted position.
Main Line- The principal line of a railway (1841), it also has the meaning "affluent area of residence" (1930s), originally that of Philadelphia, from the "main line" of the Pennsylvania Railroad, which added local stops to a string of backwater towns west of the city in late 19th century that helped turn them into fashionable suburbs.
See also related terms for railway.