mainline
Americanverb (used without object)
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to inject a narcotic, especially heroin, directly into a vein.
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to use or enjoy something without restriction.
to mainline on TV movies.
verb (used with object)
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to inject (a narcotic, especially heroin) directly into a vein.
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to use, enjoy, or imbibe (something) without restriction.
mainlining coffee all day long.
adjective
Other Word Forms
Conjugated Forms
Present
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has mainlinedperfect 3rd person singular
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have mainlinedperfect
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has been mainliningperfect progressive 3rd person singular
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have been mainliningperfect progressive
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are mainliningprogressive
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is mainliningprogressive 3rd person singular
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mainlinessingular 3rd person
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am mainliningprogressive 1st person singular
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mainliningparticiple
Past
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had mainlinedperfect
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had been mainliningperfect progressive
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was mainliningprogressive singular
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mainlinedsimple
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mainlinedparticiple
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were mainliningprogressive plural
Future
Etymology
Origin of mainline
1935–40, v., adj. use of main line
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
The game will launch on current-generation consoles, PC and Nintendo Switch 2, marking the first mainline Call of Duty to skip PlayStation 4 and Xbox One.
From BBC • May 29, 2026
Last year, he moved to North Carolina for a job with Christian Brothers Automotive, making $23 an hour and working more than 50 hours a week as a mainline technician, primarily servicing BMWs.
From The Wall Street Journal • Apr. 22, 2026
It is the main station for all services on the west coast mainline to England and also operates services throughout central Scotland.
From BBC • Mar. 10, 2026
The genius of hit songs, beyond technical artistry—and the vagaries of timing—is the ability to mainline emotion.
From The Wall Street Journal • Mar. 5, 2026
Black Muslims came in many stripes, from mainline Nation of Islam to the splinter Five Percenters.
From "Newjack: Guarding Sing Sing" by Ted Conover
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
