mainlined; mainlining; mainlines
slang
: to take by or as if by injecting into a principal vein
slang
: to mainline a narcotic drug
: being part of an established group
also
: being in the mainstream
1
: a principal highway or railroad line
2
slang
: a principal vein of the circulatory system
Examples of mainline in a Sentence
Verb
His addiction grew worse when he began mainlining.
Recent Examples on the Web
David Browne, Rolling Stone, 17 July 2024
He’s stopped taking his pills and started mainlining cheap beer.
—Erin Qualey, Vulture, 6 Mar. 2024
Glenn Taylor, Sourcing Journal, 16 July 2024
In 1990, about 36% of the Polk County population was mainline Protestant, according to the U.S. Religion Census.
—Sophie Carson, Journal Sentinel, 10 July 2024
Megan Specia, New York Times, 27 June 2024
Evergy crews are working to restore power and will first work to restore main lines that impact emergency services or a large amount of customers, the utility said in a statement Tuesday night.
—Andrea Klick, Kansas City Star, 3 July 2024
See all Example Sentences for mainline 
Verb
If Perry meant to mainline herself into the cultural conversation, mission somewhat accomplished.
—David Browne, Rolling Stone, 17 July 2024
He’s stopped taking his pills and started mainlining cheap beer.
—Erin Qualey, Vulture, 6 Mar. 2024
Adjective
The partnership would mandate either Maersk or Hapag-Lloyd to act as the sole operator of a vessel on a mainline service to reduce complexity on the routes.
—Glenn Taylor, Sourcing Journal, 16 July 2024
In 1990, about 36% of the Polk County population was mainline Protestant, according to the U.S. Religion Census.
—Sophie Carson, Journal Sentinel, 10 July 2024
Noun
For longer journeys across town, the Luas — the city’s tram system — has two main lines that extend through town and ticket machines at every stop (€1.70 for a return journey in zone 1).
—Megan Specia, New York Times, 27 June 2024
Evergy crews are working to restore power and will first work to restore main lines that impact emergency services or a large amount of customers, the utility said in a statement Tuesday night.
—Andrea Klick, Kansas City Star, 3 July 2024
See all Example Sentences for mainline
These examples are programmatically compiled from various online sources to illustrate current usage of the word 'mainline.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.
Dictionary Entries Near mainline
Cite this Entry
“Mainline.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/mainline. Accessed 26 Jul. 2024.
Copy CitationMedical Definition
mainline
1 of 2 verb
main·line
ˈmān-ˈlīn 
mainlined; mainlining
slang
: to take by or as if by injecting into a principal vein
slang
: to mainline a narcotic drug (as heroin)
main line
2 of 2 noun
slang
: a principal vein of the circulatory system
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